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Helmholtz_Test_Bench/src/socket_control.py
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197 lines
8.7 KiB
Python

from threading import Thread
import socket
import numpy as np
import src.globals as g
from src.utility import ui_print
import src.helmholtz_cage_device as helmholtz_cage_device
# --- Definition of TCP interface ---
#
# Clients should by default initialize a TCP connection to port 6677
# The commands shown must be terminated with a single \n (newline) char
# Commands may be split across multiple packets.
# Before useful commands can be sent, declare_api_version must be called.
#
# A description of the TCP api (safety limits are always enforced):
#
# set_raw_field [X comp.] [Y comp.] [Z comp.]
# Returns: 0 or 1 for success
# Accepts decimal point formatted floats, with or without scientific notation. The float() cast must understand it.
# The field units are Tesla
# This causes an additional field of the given strength to be generated, without regard for the pre-existing
# geomagnetic/external fields.
#
# set_compensated_field [X comp.] [Y comp.] [Z comp.]
# Returns: 0 or 1 for success
# Accepts decimal point formatted floats, with or without scientific notation. The float() cast must understand it.
# The field units are Tesla
# This causes a field of exactly the given magnitude to be generated by compensating external factors such as the
# geomagnetic field.
#
# set_coil_currents [X comp.] [Y comp.] [Z comp.]
# Returns: 0 or 1 for success
# Accepts decimal point formatted floats, with or without scientific notation. The float() cast must understand it.
# The field units are Ampere
# This establishes the requested current in the individual coils.
#
# get_api_version
# Returns: a string uniquely identifying each API version.
# This function can be called before declare_api_version.
# Please dont put
#
# magnetometer_field [X comp.] [Y comp.] [Z comp.]
# Returns: 1
# Accepts decimal point formatted floats, with or without scientific notation. The float() cast must understand it.
# The field units are Tesla
# Sets the state of an a virtual magnetometer object which mirrors a physical sensor providing data by means of
# this command.
#
# declare_api_version [version]
# Returns: 0 or 1 (terminated with newline)
# Declare the api version the client application was programmed for. It must be compatible with the current
# API version. This prevents unexpected behaviour by forcing programmers to specify which API they are expecting.
# This function must be called before sending HW commands.
SOCKET_INTERFACE_API_VERSION = "2"
class ClientConnectionThread(Thread):
def __init__(self, client_socket, address):
Thread.__init__(self)
self.client_socket = client_socket
self.client_address = address
# Indicates whether this thread was providing magnetometer data. If yes, set the magnetometer proxy object as
# disconnected when the socket is closed.
self.magnetometer_connection = False
# Holds proxy model to cage device if required. Is initialized lazily to prevent always blocking interface
self._cage_dev = None
self.api_compat = False # Indicates whether the client has a compatible API version
def run(self):
msg = ''
while True:
try:
raw_msg = self.client_socket.recv(2048).decode()
# Check for end of stream
if raw_msg == "":
self.client_socket.close()
if self._cage_dev:
self._cage_dev.close()
g.MAGNETOMETER.connected = False
return
# Process message
for char in raw_msg:
if char == '\n':
msg = msg.rstrip() # Some systems will try to send \r characters... looking at you windows O_O
try:
response = self.handle_msg(msg)
except Exception as e:
ui_print("An error occurred while processing a client message")
ui_print("Msg: {}".format(msg))
ui_print(e)
response = "err"
self.client_socket.sendall((response + '\n').encode('utf-8'))
msg = ''
else:
msg += char
except ConnectionResetError as e:
ui_print("A connection was closed by the client.")
self.client_socket.close()
if self._cage_dev:
self._cage_dev.close()
g.MAGNETOMETER.connected = False
return
def handle_msg(self, message):
""" Executes command logic and returns string response (for client). """
tokens = message.split(" ")
if tokens[0] == "get_api_version":
return SOCKET_INTERFACE_API_VERSION
elif tokens[0] == "declare_api_version":
if tokens[1] == SOCKET_INTERFACE_API_VERSION:
self.api_compat = True
return "1"
else:
ui_print("Declared socket API version ({}) is incompatible with current version ({})!".format(tokens[1], SOCKET_INTERFACE_API_VERSION))
return "0"
else:
# api_compat indicates we have checked the api version and are ready to accept commands
if self.api_compat:
if tokens[0] == "set_raw_field":
x = float(tokens[1])
y = float(tokens[2])
z = float(tokens[3])
field_vec = np.array([x, y, z], dtype=np.float32)
# uncompensated
self.cage_dev.set_field_raw(field_vec)
return "1"
elif tokens[0] == "set_compensated_field":
x = float(tokens[1])
y = float(tokens[2])
z = float(tokens[3])
field_vec = np.array([x, y, z], dtype=np.float32)
# compensated
self.cage_dev.set_field_compensated(field_vec)
return "1"
elif tokens[0] == "set_coil_currents":
x = float(tokens[1])
y = float(tokens[2])
z = float(tokens[3])
current_vec = np.array([x, y, z], dtype=np.float32)
self.cage_dev.set_signed_currents(current_vec)
return "1"
elif tokens[0] == "magnetometer_field":
"""The client is sending us information about the magnetometer state. This is used for some
calibration procedures for example."""
x = float(tokens[1])
y = float(tokens[2])
z = float(tokens[3])
field = np.array([x, y, z], dtype=np.float32)
g.MAGNETOMETER.field = field
self.magnetometer_connection = True
return "1"
else:
# The message given is unknown. The programmer probably did not intend for this, so display an error
# even if is not inherently problematic.
raise Exception("The command '{}' is unknown".format(tokens[0]))
else:
raise Exception("The command '{}' may not be called before 'declare_api_version'".format(tokens[0]))
@property
def cage_dev(self):
if self._cage_dev is None:
try:
self._cage_dev = g.CAGE_DEVICE.request_proxy()
except helmholtz_cage_device.DeviceBusy:
# Return none. This will cause an error and show up as "err" on the client
# A more helpful error message is shown on application side
ui_print("Socket client attempted to acquire busy device.")
return self._cage_dev
class SocketInterfaceThread(Thread):
def __init__(self):
Thread.__init__(self, daemon=True)
self.server_socket = None
# Can throw exception, which should be passed on to the instantiator of this class
self.configure_tcp_port()
def run(self):
while True:
(client_socket, address) = self.server_socket.accept()
new_thread = ClientConnectionThread(client_socket, address)
new_thread.start()
ui_print("Accepted connection from {}".format(address))
def configure_tcp_port(self):
# Creates and configures the listening port
self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.server_socket.bind(('', g.SOCKET_PORT))
self.server_socket.listen(5) # Limit to max. 5 simultaneous connections
ui_print("Listening for TCP connections on port {}".format(g.SOCKET_PORT))