TCP echo

Author: vstinner

README.rst

@@ -5,6 +5,14 @@ Asyncio documentation
 * GitHub: https://github.com/haypo/asyncio-doc
 * AsyncIO documentation is written with `Sphinx <http://www.sphinx-doc.org/>`_.
 
+
+Notes to writers
+================
+
+Tutorials should use Python 3.5 ``async`` and ``await`` keywords rather than
+``yield from``.
+
+
 Ideas
 =====
 

examples/tcp_echo_client.py

@@ -1,26 +1,21 @@
 import asyncio
 
-class EchoClientProtocol(asyncio.Protocol):
-    def __init__(self, message, loop):
-        self.message = message
-        self.loop = loop
 
-    def connection_made(self, transport):
-        transport.write(self.message.encode())
-        print('Data sent: {!r}'.format(self.message))
+async def tcp_echo_client(message, loop):
+    reader, writer = await asyncio.open_connection('127.0.0.1', 8888,
+                                                   loop=loop)
 
-    def data_received(self, data):
-        print('Data received: {!r}'.format(data.decode()))
+    print('Send: %r' % message)
+    writer.write(message.encode())
+
+    data = await reader.read(100)
+    print('Received: %r' % data.decode())
+
+    print('Close the socket')
+    writer.close()
 
-    def connection_lost(self, exc):
-        print('The server closed the connection')
-        print('Stop the event loop')
-        self.loop.stop()
 
-loop = asyncio.get_event_loop()
 message = 'Hello World!'
-coro = loop.create_connection(lambda: EchoClientProtocol(message, loop),
-                              '127.0.0.1', 8888)
-loop.run_until_complete(coro)
-loop.run_forever()
+loop = asyncio.get_event_loop()
+loop.run_until_complete(tcp_echo_client(message, loop))
 loop.close()

examples/tcp_echo_server.py

@@ -0,0 +1,30 @@
+import asyncio
+
+async def handle_echo(reader, writer):
+    data = await reader.read(100)
+    message = data.decode()
+    addr = writer.get_extra_info('peername')
+    print("Received %r from %r" % (message, addr))
+
+    print("Send: %r" % message)
+    writer.write(data)
+    await writer.drain()
+
+    print("Close the client socket")
+    writer.close()
+
+loop = asyncio.get_event_loop()
+coro = asyncio.start_server(handle_echo, '127.0.0.1', 8888, loop=loop)
+server = loop.run_until_complete(coro)
+
+# Serve requests until Ctrl+C is pressed
+print('Serving on {}'.format(server.sockets[0].getsockname()))
+try:
+    loop.run_forever()
+except KeyboardInterrupt:
+    pass
+
+# Close the server
+server.close()
+loop.run_until_complete(server.wait_closed())
+loop.close()

index.rst

@@ -12,7 +12,6 @@ Chapiter 1: First steps with asyncio
    hello_world.rst
    hello_clock.rst
    http_client.rst
-   tcp_echo_client.rst
    twisted.rst
    getting_help.rst
 
@@ -23,6 +22,7 @@ Chapiter 2: Advanced topics
 .. toctree::
    :maxdepth: 2
 
+   tcp_echo.rst
    threads.rst
    producer_consumer.rst
    debug_mode.rst

tcp_echo.rst

@@ -0,0 +1,18 @@
+++++++++++++++++++++++++++
+TCP echo client and server
+++++++++++++++++++++++++++
+
+TCP echo client
+---------------
+
+TCP echo client using streams:
+
+.. literalinclude:: examples/tcp_echo_client.py
+
+
+TCP echo server
+---------------
+
+TCP echo server using streams:
+
+.. literalinclude:: examples/tcp_echo_server.py