[Python-checkins] cpython: asyncio doc: write a complete TCP echo example, client and server

Tue Dec 3 01:47:08 CET 2013

http://hg.python.org/cpython/rev/c17a04f85c0e
changeset: 87726:c17a04f85c0e
user: Victor Stinner <victor.stinner at gmail.com>
date: Tue Dec 03 01:46:39 2013 +0100
summary:
 asyncio doc: write a complete TCP echo example, client and server
Example based on tcp_echo.py example from Tulip source code.
files:
 Doc/library/asyncio-eventloop.rst | 2 +-
 Doc/library/asyncio-protocol.rst | 116 +++++++++++------
 2 files changed, 72 insertions(+), 46 deletions(-)

diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst
--- a/Doc/library/asyncio-eventloop.rst
+++ b/Doc/library/asyncio-eventloop.rst
@@ -150,7 +150,7 @@
 
 
 Creating connections
-^^^^^^^^^^^^^^^^^^^^
+--------------------
 
 .. method:: BaseEventLoop.create_connection(protocol_factory, host=None, port=None, \*, ssl=None, family=0, proto=0, flags=0, sock=None, local_addr=None, server_hostname=None)
 
diff --git a/Doc/library/asyncio-protocol.rst b/Doc/library/asyncio-protocol.rst
--- a/Doc/library/asyncio-protocol.rst
+++ b/Doc/library/asyncio-protocol.rst
@@ -20,8 +20,8 @@
 the transport's kind.
 
 
-BaseTransport: Methods common to all transports
------------------------------------------------
+BaseTransport
+-------------
 
 .. class:: BaseTransport
 
@@ -75,8 +75,8 @@
 - ``'subprocess'``: :class:`subprocess.Popen` instance
 
 
-ReadTransport: Methods of readable streaming transports
--------------------------------------------------------
+ReadTransport
+-------------
 
 .. class:: ReadTransport
 
@@ -94,8 +94,8 @@
 will be called once again if some data is available for reading.
 
 
-WriteTransport: Methods of writable streaming transports
---------------------------------------------------------
+WriteTransport
+--------------
 
 .. class:: WriteTransport
 
@@ -159,8 +159,8 @@
 (e.g. SSL) doesn't support half-closes.
 
 
-DatagramTransport: Methods of datagram transports
--------------------------------------------------
+DatagramTransport
+-----------------
 
 .. method:: DatagramTransport.sendto(data, addr=None)
 
@@ -179,8 +179,8 @@
 called with :const:`None` as its argument.
 
 
-Methods of subprocess transports
---------------------------------
+BaseSubprocessTransport
+-----------------------
 
 .. class:: BaseSubprocessTransport
 
@@ -224,8 +224,8 @@
 On Windows, this method is an alias for :meth:`terminate`.
 
 
-Stream reader
--------------
+StreamWriter
+------------
 
 .. class:: StreamWriter(transport, protocol, reader, loop)
 
@@ -286,8 +286,8 @@
 see :meth:`WriteTransport.write_eof`.
 
 
-Stream writer
--------------
+StreamReader
+------------
 
 .. class:: StreamReader(limit=_DEFAULT_LIMIT, loop=None)
 
@@ -418,11 +418,8 @@
 Called when the child process has exited.
 
 
-Data reception callbacks
-------------------------
-
 Streaming protocols
-^^^^^^^^^^^^^^^^^^^
+-------------------
 
 The following callbacks are called on :class:`Protocol` instances:
 
@@ -458,7 +455,7 @@
 and, if called, :meth:`data_received` won't be called after it.
 
 Datagram protocols
-^^^^^^^^^^^^^^^^^^
+------------------
 
 The following callbacks are called on :class:`DatagramProtocol` instances.
 
@@ -576,40 +573,69 @@
 
 This function returns a :ref:`coroutine <coroutine>`.
 
-Example: Echo server
---------------------
 
-A :class:`Protocol` implementing an echo server::
+Protocol example: TCP echo client and server
+============================================
 
- class EchoServer(asyncio.Protocol):
+Echo server
+-----------
 
- TIMEOUT = 5.0
+TCP echo server example::
 
- def timeout(self):
- print('connection timeout, closing.')
- self.transport.close()
+ import asyncio
 
- def connection_made(self, transport):
- print('connection made')
- self.transport = transport
+ class EchoServer(asyncio.Protocol):
+ def timeout(self):
+ print('connection timeout, closing.')
+ self.transport.close()
 
- # start 5 seconds timeout timer
- self.h_timeout = asyncio.get_event_loop().call_later(
- self.TIMEOUT, self.timeout)
+ def connection_made(self, transport):
+ print('connection made')
+ self.transport = transport
 
- def data_received(self, data):
- print('data received: ', data.decode())
- self.transport.write(b'Re: ' + data)
+ # close the client connection after 2 seconds
+ asyncio.get_event_loop().call_later(2.0, self.timeout)
 
- # restart timeout timer
- self.h_timeout.cancel()
- self.h_timeout = asyncio.get_event_loop().call_later(
- self.TIMEOUT, self.timeout)
+ def data_received(self, data):
+ print('data received:', data.decode())
+ self.transport.write(data)
 
- def eof_received(self):
- pass
+ def connection_lost(self, exc):
+ print('connection lost')
 
- def connection_lost(self, exc):
- print('connection lost:', exc)
- self.h_timeout.cancel()
 
+ loop = asyncio.get_event_loop()
+ f = loop.create_server(EchoServer, '127.0.0.1', 8888)
+ s = loop.run_until_complete(f)
+ print('serving on', s.sockets[0].getsockname())
+ loop.run_forever()
+
+
+Echo client
+-----------
+
+TCP echo client example::
+
+ import asyncio
+
+ class EchoClient(asyncio.Protocol):
+ message = 'This is the message. It will be echoed.'
+
+ def connection_made(self, transport):
+ self.transport = transport
+ self.transport.write(self.message.encode())
+ print('data sent:', self.message)
+
+ def data_received(self, data):
+ print('data received:', data.decode())
+
+ def connection_lost(self, exc):
+ print('connection lost')
+ asyncio.get_event_loop().stop()
+
+ loop = asyncio.get_event_loop()
+ task = loop.create_connection(EchoClient, '127.0.0.1', 8888)
+ loop.run_until_complete(task)
+ loop.run_forever()
+ loop.close()
+
-- 
Repository URL: http://hg.python.org/cpython
