def connect(self):
"""Establish WebSocket connection to the ROS server defined for this factory.
Returns:
async_task: The async task for the connection.
"""
LOGGER.debug('Started to connect...')
socket = ClientWebSocket()
connect_task = socket.ConnectAsync(self.url,
self.manager.cancellation_token)
protocol = CliRosBridgeProtocol(self, socket)
connect_task.ContinueWith(protocol.on_open)
return connect_task
class Client_Net():
"""A Websoket client using .NET that works in a simple synchronous fashion
Parameters
----------
host: str, optional
The host ip of remote server.
Default is ``127.0.0.1``.
port : int, optional
The port number of remote server to connect to.
Default is ``9000``.
"""
def __init__(self, host='127.0.0.1', port=9000):
"""init the client, wait until it successfully connected to server"""
scheme = 'ws'
builder = UriBuilder(scheme, host, port)
uri = builder.Uri
self.token = CancellationTokenSource().Token
self.socket = ClientWebSocket()
task = self.socket.ConnectAsync(uri, self.token)
task.Wait()
print('connected to cloud using .NET client!')
def disconnect(self):
"""disconnect from server"""
task = self.socket.CloseAsync(
WebSocketCloseStatus.NormalClosure, 'script finished', self.token)
task.Wait()
print('closed!')
def send(self, payload):
"""send a message to server and wait until sent"""
if self.socket.State != WebSocketState.Open:
raise RuntimeError('Connection is not open.')
message_buffer = Encoding.UTF8.GetBytes(payload)
message_length = len(message_buffer)
chunks_count = int(math.ceil(float(message_length) / SEND_CHUNK_SIZE))
i = 0
while True:
# print('sending chunk', i)
offset = SEND_CHUNK_SIZE * i
is_last_message = (i == chunks_count - 1)
if is_last_message:
count = message_length - offset
else:
count = SEND_CHUNK_SIZE
message_chunk = ArraySegment[Byte](message_buffer, offset, count)
task = self.socket.SendAsync(
message_chunk, WebSocketMessageType.Text, is_last_message, self.token)
task.Wait()
i += 1
if is_last_message:
return True
def receive(self):
"""listen to a message until received one"""
if self.socket.State != WebSocketState.Open:
raise RuntimeError('Connection is not open.')
chunks = []
while True:
# print('receive chunk')
buffer = Array.CreateInstance(Byte, RECEIVE_CHUNK_SIZE)
task = self.socket.ReceiveAsync(
ArraySegment[Byte](buffer), self.token)
task.Wait()
chunk = Encoding.UTF8.GetString(buffer)
chunks.append(chunk.rstrip('\x00'))
if task.Result.EndOfMessage:
return ''.join(chunks)