使用Python socket模块编写WebSocket服务器(浏览器作客户端)

环境：Python 3.6.5，Chrome 81.0.4044.138
说明：并非直接使用websockets模块来编写

0x00 前言

公司项目中有很多要求实时状态的功能，且响应数据很小。现有方式采用ajax轮询，较浪费资源，故开始探索socket编程。此文仅为初步探索，实现功能仅为client -> server -> client。

0x01 参考文章

Python 3.5.2实现websocket服务端
用Python实现一个简单的WebSocket服务器
易百教程：Websocket教程™

0x02 服务端代码

# 文件名：Server.py
import socket
import threading
import hashlib
import base64
import struct
import time

PRINT_LOG = True
GUID = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'


# 将由js提交的bytes类型的消息转为str
def bytes2str(msg):
    local_code_length = msg[1] & 127
    if local_code_length == 126:
        masks = msg[4:8]
        data = msg[8:]
    elif local_code_length == 127:
        masks = msg[10:14]
        data = msg[14:]
    else:
        masks = msg[2:6]
        data = msg[6:]
    en_bytes = b""
    cn_bytes = []
    for i, d in enumerate(data):
        nv = chr(d ^ masks[i % 4])
        nv_bytes = nv.encode()
        nv_len = len(nv_bytes)
        if nv_len == 1:
            en_bytes += nv_bytes
        else:
            en_bytes += b'%s'
            cn_bytes.append(ord(nv_bytes.decode()))
    if len(cn_bytes) > 2:
        cn_str = ""
        cn_len = len(cn_bytes)
        count = int(cn_len / 3)
        for x in range(count):
            i = x * 3
            b = bytes([cn_bytes[i], cn_bytes[i + 1], cn_bytes[i + 2]])
            cn_str += b.decode()
        new = en_bytes.replace(b'%s%s%s', b'%s')
        new = new.decode()
        rst = (new % tuple(list(cn_str)))
    else:
        rst = en_bytes.decode()
    return rst


# 根据js发送的报文计算code_length和header_length并返回
def calculate_data_length(msg):
    local_code_length = msg[1] & 127
    if local_code_length == 126:
        local_code_length = struct.unpack('>H', msg[2:4])[0]
        local_header_length = 8
    elif local_code_length == 127:
        local_code_length = struct.unpack('>Q', msg[2:10])[0]