Stream::send() (#6979)

libraries/ESP8266WiFi/examples/WiFiEcho/echo-client.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+
+import os
+import asyncio
+
+# 512 bytes
+message = bytearray(512);
+bufsize=len(message)
+print('message len=', bufsize)
+
+global recv
+recv = 0
+
+async def tcp_echo_open (ip, port):
+    return await asyncio.open_connection(ip, port)
+
+async def tcp_echo_sender(message, writer):
+    print('Writer started')
+    while True:
+        writer.write(message)
+        await writer.drain()
+
+async def tcp_echo_receiver(message, reader):
+    global recv
+    print('Reader started')
+    while True:
+        data = ''.encode('utf8')
+        while len(data) < bufsize:
+            data += await reader.read(bufsize - len(data))
+        recv += len(data);
+        if data != message:
+            print('error')
+
+async def tcp_stat():
+    global recv
+    dur = 0
+    loopsec = 2
+    while True:
+        last = recv
+        await asyncio.sleep(loopsec) # drifting
+        dur += loopsec
+        print('BW=', (recv - last) * 2 * 8 / 1024 / loopsec, 'Kibits/s avg=', recv * 2 * 8 / 1024 / dur)
+
+loop = asyncio.get_event_loop()
+reader, writer = loop.run_until_complete(tcp_echo_open('echo23.local', 23))
+loop.create_task(tcp_echo_receiver(message, reader))
+loop.create_task(tcp_echo_sender(message, writer))
+loop.create_task(tcp_stat())
+loop.run_forever()