first commit

server.py

@@ -0,0 +1,64 @@
+
+import socket
+import selectors
+import types
+sel = selectors.DefaultSelector()
+host = '127.0.0.1'
+port = 80
+lsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+lsock.bind((host, port))
+lsock.listen()
+print('listening on', (host, port))
+lsock.setblocking(False)
+sel.register(lsock, selectors.EVENT_READ, data=None)
+
+clients = []
+
+def accept_wrapper(sock):
+    conn, addr = sock.accept()  # Should be ready to read
+    print('accepted connection from', addr)
+    conn.setblocking(False)
+    client = types.SimpleNamespace(addr=addr, inb='', outb='')
+    events = selectors.EVENT_READ | selectors.EVENT_WRITE
+    sel.register(conn, events, data=client)
+    clients.append(client)
+
+def service_connection(key, mask):
+    sock = key.fileobj
+    data = key.data
+
+    if mask & selectors.EVENT_READ:
+        recv_data = sock.recv(1024)  # Should be ready to read
+        if recv_data:
+            m = recv_data.decode("utf-8")
+            messages = m.split("\n")
+            if len(messages) > 1:
+                messages[0]= data.inb + messages[0]
+                data.inb = ""
+            for message in messages[:-1]:
+                #send to other clients
+                for client in clients:
+                    if client.addr != data.addr:
+                        client.outb += message + "\n"
+            data.inb += messages[-1]
+            
+        else:
+            print('closing connection to', data.addr)
+            sel.unregister(sock)
+            sock.close()
+    if mask & selectors.EVENT_WRITE:
+        if data.outb:
+            print('echoing', data.outb, 'to', data.addr)
+            sent = sock.send(data.outb.encode('utf-8'))  # Should be ready to write
+            data.outb = data.outb[sent:]
+
+while True:
+    events = sel.select(timeout=None)
+    for key, mask in events:
+        if key.data is None:
+            accept_wrapper(key.fileobj)
+        else:
+            service_connection(key, mask)
+            
+            
+            

test_client.py

@@ -0,0 +1,50 @@
+import selectors
+import socket
+import types
+import time
+HOST = '127.0.0.1'  # The server's hostname or IP address
+PORT = 80        # The port used by the server
+sel = selectors.DefaultSelector()
+i = 0
+message = ""
+def service_connection(key, mask, message):
+    sock = key.fileobj
+    data = key.data
+    if mask & selectors.EVENT_READ:
+        recv_data = sock.recv(1024)  # Should be ready to read
+        if recv_data:
+            print('received', repr(recv_data),flush=True)
+            
+    if mask & selectors.EVENT_WRITE:
+        if message:
+            data.outb += message
+            message = ""
+            print('sending', repr(data.outb))
+            sent = sock.send(data.outb.encode('utf-8'))  # Should be ready to write
+            data.outb = data.outb[sent:]
+
+def start_connection(host, port):
+    server_addr = (host, port)
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.setblocking(False)
+    sock.connect_ex(server_addr)
+    events = selectors.EVENT_READ | selectors.EVENT_WRITE
+    data = types.SimpleNamespace(outb='')
+    sel.register(sock, events, data=data)
+
+
+start_connection(HOST, PORT)
+while True:
+    events = sel.select(timeout=None)
+    for key, mask in events:
+        if key.data is None:
+            pass
+        else:
+            service_connection(key, mask, message)
+            message = ""
+    
+    i += 1
+    if i % 10 == 0:
+        message = f"hello {i}\n"
+            
+