初步完成lab3代码

Labs/Lab3/src/Receiver.py

@@ -0,0 +1,58 @@
+import socket
+import random
+
+class NetworkLayer:
+    def __init__(self, host="0.0.0.0", port=31415) -> None:
+        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.socket.connect((host, port))
+
+    def udt_send(self, data:str):
+        self.socket.send(data.encode())
+
+    def udt_rcv(self) -> str:
+        while True:
+            message = self.socket.recv(1024).decode("utf-8")
+            return message
+                
+            
+
+class ApplicationLayer:
+    def __init__(self) -> None:
+        self.data = list()
+
+
+class Receiver:
+    def __init__(self, networkLayer:NetworkLayer, applicationLayer:ApplicationLayer):
+        self.expected_seq_num = 0
+        self.networkLayer = networkLayer
+        self.applicationLayer = applicationLayer
+        
+    def deliver_data(self, data, seq_num):
+        if seq_num == self.expected_seq_num:
+            self.applicationLayer.data.append(data)
+            self.udt_send(seq_num)
+            self.expected_seq_num += 1
+        else:
+            self.udt_send(self.expected_seq_num - 1)
+
+    def udt_send(self, ack_num):
+        if random.random() > 0.2:
+            self.networkLayer.socket.send(str(ack_num).encode())
+
+    def extract(self, message:str):
+        parts = message.split(" ")
+        seq_num = int(parts[0])
+        data = parts[1]
+        return seq_num, data
+
+if __name__ == "__main__":
+    networkLayer = NetworkLayer()
+    applicationLayer = ApplicationLayer()
+    receiver = Receiver(networkLayer, applicationLayer)
+    while True:
+        message = networkLayer.udt_rcv()
+        if message:
+            seq_num, data = receiver.extract(message)
+            receiver.deliver_data(data, seq_num)
+
+