circuitpython/extmod/uasyncio/stream.py
Damien George 441460d81f extmod/uasyncio: Add StreamReader.readexactly(n) method.
It raises on EOFError instead of an IncompleteReadError (which is what
CPython does).  But the latter is derived from EOFError so code compatible
with MicroPython and CPython can be written by catching EOFError (eg see
included test).

Fixes issue #6156.

Signed-off-by: Damien George <damien@micropython.org>
2020-07-25 23:10:05 +10:00

159 lines
4.1 KiB
Python

# MicroPython uasyncio module
# MIT license; Copyright (c) 2019-2020 Damien P. George
from . import core
class Stream:
def __init__(self, s, e={}):
self.s = s
self.e = e
self.out_buf = b""
def get_extra_info(self, v):
return self.e[v]
async def __aenter__(self):
return self
async def __aexit__(self, exc_type, exc, tb):
await self.close()
def close(self):
pass
async def wait_closed(self):
# TODO yield?
self.s.close()
async def read(self, n):
yield core._io_queue.queue_read(self.s)
return self.s.read(n)
async def readexactly(self, n):
r = b""
while n:
yield core._io_queue.queue_read(self.s)
r2 = self.s.read(n)
if r2 is not None:
if not len(r2):
raise EOFError
r += r2
n -= len(r2)
return r
async def readline(self):
l = b""
while True:
yield core._io_queue.queue_read(self.s)
l2 = self.s.readline() # may do multiple reads but won't block
l += l2
if not l2 or l[-1] == 10: # \n (check l in case l2 is str)
return l
def write(self, buf):
self.out_buf += buf
async def drain(self):
mv = memoryview(self.out_buf)
off = 0
while off < len(mv):
yield core._io_queue.queue_write(self.s)
ret = self.s.write(mv[off:])
if ret is not None:
off += ret
self.out_buf = b""
# Stream can be used for both reading and writing to save code size
StreamReader = Stream
StreamWriter = Stream
# Create a TCP stream connection to a remote host
async def open_connection(host, port):
from uerrno import EINPROGRESS
import usocket as socket
ai = socket.getaddrinfo(host, port)[0] # TODO this is blocking!
s = socket.socket()
s.setblocking(False)
ss = Stream(s)
try:
s.connect(ai[-1])
except OSError as er:
if er.args[0] != EINPROGRESS:
raise er
yield core._io_queue.queue_write(s)
return ss, ss
# Class representing a TCP stream server, can be closed and used in "async with"
class Server:
async def __aenter__(self):
return self
async def __aexit__(self, exc_type, exc, tb):
self.close()
await self.wait_closed()
def close(self):
self.task.cancel()
async def wait_closed(self):
await self.task
async def _serve(self, cb, host, port, backlog):
import usocket as socket
ai = socket.getaddrinfo(host, port)[0] # TODO this is blocking!
s = socket.socket()
s.setblocking(False)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(ai[-1])
s.listen(backlog)
self.task = core.cur_task
# Accept incoming connections
while True:
try:
yield core._io_queue.queue_read(s)
except core.CancelledError:
# Shutdown server
s.close()
return
try:
s2, addr = s.accept()
except:
# Ignore a failed accept
continue
s2.setblocking(False)
s2s = Stream(s2, {"peername": addr})
core.create_task(cb(s2s, s2s))
# Helper function to start a TCP stream server, running as a new task
# TODO could use an accept-callback on socket read activity instead of creating a task
async def start_server(cb, host, port, backlog=5):
s = Server()
core.create_task(s._serve(cb, host, port, backlog))
return s
################################################################################
# Legacy uasyncio compatibility
async def stream_awrite(self, buf, off=0, sz=-1):
if off != 0 or sz != -1:
buf = memoryview(buf)
if sz == -1:
sz = len(buf)
buf = buf[off : off + sz]
self.write(buf)
await self.drain()
Stream.aclose = Stream.wait_closed
Stream.awrite = stream_awrite
Stream.awritestr = stream_awrite # TODO explicitly convert to bytes?