使用python实现基于socket的滑动窗口模拟

这里提供一个简单的基于socket的滑动窗口模拟实现，代码如下：

import socket
import time

# 定义发送方和接收方的IP和端口号
sender_ip = '127.0.0.1'
sender_port = 8888
receiver_ip = '127.0.0.1'
receiver_port = 9999

# 定义数据包大小和窗口大小
packet_size = 1024
window_size = 4

# 创建UDP socket
sender_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
receiver_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

# 绑定接收方的IP和端口号
receiver_socket.bind((receiver_ip, receiver_port))

# 定义发送方和接收方的初始序号和确认序号
sender_seq = 0
sender_ack = 0
receiver_seq = 0
receiver_ack = 0

# 定义发送方和接收方的窗口
sender_window = []
receiver_window = []

# 发送数据
def send_data(data):
    global sender_seq, sender_ack, sender_window
    # 将数据分割成数据包
    packets = [data[i:i+packet_size] for i in range(0, len(data), packet_size)]
    for packet in packets:
        # 将数据包打包成字节串
        packet_bytes = str(sender_seq).encode() + b':' + packet
        # 发送数据包
        sender_socket.sendto(packet_bytes, (receiver_ip, receiver_port))
        # 将数据包加入发送方窗口
        sender_window.append(packet_bytes)
        # 更新发送方序号
        sender_seq += len(packet)
        # 如果发送方窗口大小超过了窗口大小，等待接收方的确认，直到发送方窗口大小小于等于窗口大小
        while len(sender_window) > window_size:
            time.sleep(0.1)
            receive_ack()

# 接收数据
def receive_data():
    global receiver_seq, receiver_ack, receiver_window
    # 接收数据包
    packet_bytes, _ = receiver_socket.recvfrom(packet_size + 32)
    # 解析数据包
    seq_bytes, packet = packet_bytes.split(b':', 1)
    seq = int(seq_bytes.decode())
    # 如果序号不是期望的序号，直接丢弃数据包
    if seq != receiver_seq:
        return
    # 将数据包加入接收方窗口
    receiver_window.append(packet)
    # 更新接收方序号
    receiver_seq += len(packet)
    # 更新接收方确认序号
    receiver_ack = receiver_seq
    # 发送确认消息
    send_ack()

# 发送确认消息
def send_ack():
    global receiver_ack
    # 发送确认消息，确认序号为接收方序号
    receiver_socket.sendto(str(receiver_ack).encode(), (sender_ip, sender_port))

# 接收确认消息
def receive_ack():
    global sender_ack, sender_window
    # 接收确认消息
    ack_bytes, _ = sender_socket.recvfrom(packet_size)
    # 解析确认消息
    ack = int(ack_bytes.decode())
    # 更新发送方确认序号
    sender_ack = ack
    # 从发送方窗口中删除已经确认的数据包
    while sender_window and int(sender_window[0].split(b':', 1)[0].decode()) < sender_ack:
        sender_window.pop(0)

if __name__ == '__main__':
    # 发送数据
    send_data('hello world')
    # 接收数据
    while True:
        receive_data()
        if receiver_ack == sender_seq:
            break
    # 关闭socket
    sender_socket.close()
    receiver_socket.close()

该代码实现了一个简单的滑动窗口模拟，通过UDP socket发送和接收数据包，并实现了滑动窗口的功能。在发送数据时，将数据分割成数据包，并将数据包打包成字节串发送。在接收数据时，解析数据包，并将数据包加入接收方窗口，更新接收方序号和确认序号，然后发送确认消息。在发送确认消息时，确认序号为接收方序号。在接收确认消息时，更新发送方确认序号，并从发送方窗口中删除已经确认的数据包。通过循环接收数据，并等待接收方确认，直到所有数据都被接收方确认。最后关闭socket。