Commit 3d19adf9 authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

examples/network: Split recv- and read-based HTTP servers.

Name recv() based a "simplistic", as it can't work robustly in every
environment. All this is to let people concentreate on proper, read()-
based one (and to turn recv() based into a "negative showcase",
explaining what are the pitfalls of such approach).
parent d79342d3
......@@ -10,7 +10,7 @@ HTTP/1.0 200 OK
Hello #%d from MicroPython!
"""
def main(use_stream=False):
def main(micropython_optimize=False):
s = socket.socket()
# Binding to all interfaces - server will be accessible to other hosts!
......@@ -26,26 +26,37 @@ def main(use_stream=False):
counter = 0
while True:
res = s.accept()
client_s = res[0]
client_sock = res[0]
client_addr = res[1]
print("Client address:", client_addr)
print("Client socket:", client_s)
print("Request:")
if use_stream:
# MicroPython socket objects support stream (aka file) interface
# directly.
req = client_s.readline()
print(req)
while True:
h = client_s.readline()
if h == b"" or h == b"\r\n":
break
print(h)
client_s.write(CONTENT % counter)
print("Client socket:", client_sock)
if not micropython_optimize:
# To read line-oriented protocol (like HTTP) from a socket (and
# avoid short read problem), it must be wrapped in a stream (aka
# file-like) object. That's how you do it in CPython:
client_stream = client_sock.makefile("rwb")
else:
print(client_s.recv(4096))
client_s.send(CONTENT % counter)
client_s.close()
# .. but MicroPython socket objects support stream interface
# directly, so calling .makefile() method is not required. If
# you develop application which will run only on MicroPython,
# especially on a resource-constrained embedded device, you
# may take this shortcut to save resources.
client_stream = client_sock
print("Request:")
req = client_stream.readline()
print(req)
while True:
h = client_stream.readline()
if h == b"" or h == b"\r\n":
break
print(h)
client_stream.write(CONTENT % counter)
client_stream.close()
if not micropython_optimize:
client_sock.close()
counter += 1
print()
......
try:
import usocket as socket
except:
import socket
CONTENT = b"""\
HTTP/1.0 200 OK
Hello #%d from MicroPython!
"""
def main():
s = socket.socket()
ai = socket.getaddrinfo("0.0.0.0", 8080)
addr = ai[0][-1]
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(addr)
s.listen(5)
print("Listening, connect your browser to http://<this_host>:8080/")
counter = 0
while True:
res = s.accept()
client_s = res[0]
client_addr = res[1]
req = client_s.recv(4096)
print("Request:")
print(req)
client_s.send(CONTENT % counter)
client_s.close()
counter += 1
print()
main()
#
# MicroPython http_server_simplistic.py example
#
# This example shows how to write the smallest possible HTTP
# server in MicroPython. With comments and convenience code
# removed, this example can be compressed literally to ten
# lines. There's a catch though - read comments below for
# details, and use this code only for quick hacks, preferring
# http_server.py for "real thing".
#
try:
import usocket as socket
except:
import socket
CONTENT = b"""\
HTTP/1.0 200 OK
Hello #%d from MicroPython!
"""
def main():
s = socket.socket()
# Bind to (allow to be connected on ) all interfaces. This means
# this server will be accessible to other hosts on your local
# network, and if your server has direct (non-firewalled) connection
# to the Internet, then to anyone on the Internet. We bind to all
# interfaces to let this example work easily on embedded MicroPython
# targets, which you will likely access from another machine on your
# local network. Take care when running this on an Internet-connected
# machine though! Replace "0.0.0.0" with "127.0.0.1" if in doubt, to
# make the server accessible only on the machine it runs on.
ai = socket.getaddrinfo("0.0.0.0", 8080)
print("Bind address info:", ai)
addr = ai[0][-1]
# A port on which a socket listened remains inactive during some time.
# This means that if you run this sample, terminate it, and run again
# you will likely get an error. To avoid this timeout, set SO_REUSEADDR
# socket option.
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(addr)
s.listen(5)
print("Listening, connect your browser to http://<this_host>:8080/")
counter = 0
while True:
res = s.accept()
client_s = res[0]
client_addr = res[1]
print("Client address:", client_addr)
print("Client socket:", client_s)
# We assume here that .recv() call will read entire HTTP request
# from client. This is usually true, at least on "big OS" systems
# like Linux/MacOS/Windows. But that doesn't have to be true in
# all cases, in particular on embedded systems, when there can
# easily be "short recv", where it returns much less than requested
# data size. That's why this example is called "simplistic" - it
# shows that writing a web server in Python that *usually works* is
# ten lines of code, and you can use this technique for quick hacks
# and experimentation. But don't do it like that in production
# applications - instead, parse HTTP request properly, as shown
# by http_server.py example.
req = client_s.recv(4096)
print("Request:")
print(req)
client_s.send(CONTENT % counter)
client_s.close()
counter += 1
print()
main()
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