esockets
esockets is a python socket.socket server. There are many socket.socket python modules out there, I choose to write this because I failed to find one that met my requirements and at the same time was easy enough to understand. esockets uses non-blocking sockets with select.epoll() to check for read/write/error socket changes.
When to use esockets?
esockets is written for one purpose above all, servers that need to support a high client count. An esockets server client count is restricted by the amount of file descriptors availible on the system.
Important notes about changes
- 2015-12-15: Changed the name of some of the "on" functions.
- 2015-12-17: Several choices added when calling ESocketS.Socket()
- 2015-12-22: Large update, I expect most programs previously built on this module will not work as is anymore
- 2016-02-14: Updated the readme file
How to get started
Installation
pip install esocketsUpdate
At the moment (2016-02-14) this module is still new. As I try to integrate it into my other projects I usually find something to improve. So to get the latest version do
pip install esockets --upgradeSee https://github.com/Zaeb0s/epoll-socket-server for the latest changes
Basic setup
The user communicates with the ServerSocket class using two functions (handle_incoming and handle_readable) that returns True/False.
The following is a simple example of an echo server
#!/bin/env python3
import esockets
def handle_incoming(client, address):
"""
Return True: The client is accepted and the server starts polling for messages
Return False: The server disconnects the client.
"""
client.sendall(b'SERVER: Connection accepted!\n')
return True
def handle_readable(client):
"""
Return True: The client is re-registered to the selector object.
Return False: The server disconnects the client.
"""
data = client.recv(1028)
if data == b'':
return False
client.sendall(b'SERVER: ' + data)
return True
server = esockets.SocketServer(handle_incoming=handle_incoming,
handle_readable=handle_readable)
server.start()
print('Server started on: {}:{}'.format(server.host, server.port))Customizable variables
When the SocketServer is initiated the following customizable variables are set if not otherwise specified
| Variable | Description | Default |
|---|---|---|
| port | The server port | 1234 |
| host | The server host | Using the socket modules socket.gethostbyname(socket.gethostname()) |
| queue_size | Max number of clients awaiting to be accepted | 1000 |
| block_time | Maximum block time within each selector and queue objects | 2 |
| selector | A selectors object to determine which type to use | selectors.EpollSelector |
| max_subthreads | Maximum number of threads started in addition to the four mainthreads | -1 (Unlimited) |
Calling with all default values would then look like this
server = esockets.SocketServer( port=1234,
host=socket.gethostbyname(socket.gethostname()),
queue_size=1000,
block_time=2,
selector=selectors.EpollSelector,
handle_readable=lambda client: True,
handle_incoming=lambda client, address: True,
max_subthreads=-1):Planned releases
- ewebsockets - A Websocket server based on esockets and the RFC6455 websocket protocol
Contact
Find something hard to understand? Do you have any suggestions of further improvement? If so do not hesitate to contact me on christoffer_zakrisson@hotmail.com
