Adafruit_CircuitPython_ESP_.../adafruit_espatcontrol/adafruit_espatcontrol_socket.py
2020-03-15 17:22:41 -04:00

90 lines
3.3 KiB
Python

"""A 'socket' compatible interface thru the ESP AT command set"""
from micropython import const
_the_interface = None # pylint: disable=invalid-name
def set_interface(iface):
"""Helper to set the global internet interface"""
global _the_interface # pylint: disable=global-statement, invalid-name
_the_interface = iface
SOCK_STREAM = const(1)
AF_INET = const(2)
# pylint: disable=too-many-arguments, unused-argument
def getaddrinfo(host, port, family=0, socktype=0, proto=0, flags=0):
"""Given a hostname and a port name, return a 'socket.getaddrinfo'
compatible list of tuples. Honestly, we ignore anything but host & port"""
if not isinstance(port, int):
raise RuntimeError("port must be an integer")
ipaddr = _the_interface.nslookup(host)
return [(AF_INET, socktype, proto, "", (ipaddr, port))]
# pylint: enable=too-many-arguments, unused-argument
# pylint: disable=unused-argument, redefined-builtin, invalid-name
class socket:
"""A simplified implementation of the Python 'socket' class, for connecting
through an interface to a remote device"""
def __init__(self, family=AF_INET, type=SOCK_STREAM, proto=0, fileno=None):
if family != AF_INET:
raise RuntimeError("Only AF_INET family supported")
if type != SOCK_STREAM:
raise RuntimeError("Only SOCK_STREAM type supported")
self._buffer = b""
self.settimeout(0)
def connect(self, address, conntype=None):
"""Connect the socket to the 'address' (which should be dotted quad IP). 'conntype'
is an extra that may indicate SSL or not, depending on the underlying interface"""
host, port = address
if not _the_interface.socket_connect(
conntype, host, port, keepalive=10, retries=3
):
raise RuntimeError("Failed to connect to host", host)
self._buffer = b""
def send(self, data): # pylint: disable=no-self-use
"""Send some data to the socket"""
_the_interface.socket_send(data)
def readline(self):
"""Attempt to return as many bytes as we can up to but not including '\r\n'"""
if b"\r\n" not in self._buffer:
# there's no line already in there, read some more
self._buffer = self._buffer + _the_interface.socket_receive(timeout=3)
# print(self._buffer)
firstline, self._buffer = self._buffer.split(b"\r\n", 1)
return firstline
def recv(self, num=0):
"""Read up to 'num' bytes from the socket, this may be buffered internally!
If 'num' isnt specified, return everything in the buffer."""
if num == 0:
# read as much as we can
ret = self._buffer + _the_interface.socket_receive(timeout=self._timeout)
self._buffer = b""
else:
ret = self._buffer[:num]
self._buffer = self._buffer[num:]
return ret
def close(self):
"""Close the socket, after reading whatever remains"""
# read whatever's left
self._buffer = self._buffer + _the_interface.socket_receive(
timeout=self._timeout
)
_the_interface.socket_disconnect()
def settimeout(self, value):
"""Set the read timeout for sockets, if value is 0 it will block"""
self._timeout = value
# pylint: enable=unused-argument, redefined-builtin, invalid-name