8.4.2. TCP/IP related methods

8.4.2.1. Serializing object to bytes and back

Created the 20/10/2023

@author: Sebastien Weber

class pymodaq.utils.tcp_ip.serializer.DeSerializer(bytes_string: Union[bytes, Socket] = None)[source]

Used to DeSerialize bytes to python objects, numpy arrays and PyMoDAQ Axis, DataWithAxes and DataToExport objects

Parameters: bytes_string (bytes or Socket) – the bytes string to deserialize into an object: int, float, string, arrays, list, Axis, DataWithAxes… Could also be a Socket object reading bytes from the network having a get_first_nbytes method

See also

SocketString, Socket

Methods

`axis_deserialization`()	Convert bytes into an Axis object
`boolean_deserialization`()	Convert bytes into a boolean object
`bytes_to_int`(bytes_string)	Convert a bytes of length 4 into an integer
`bytes_to_nd_array`(data, dtype, shape)	Convert bytes to a ndarray given a certain numpy dtype and shape
`bytes_to_scalar`(data, dtype)	Convert bytes to a scalar given a certain numpy dtype
`dte_deserialization`()	Convert bytes into a DataToExport object
`dwa_deserialization`()	Convert bytes into a DataWithAxes object
`list_deserialization`()	Convert bytes into a list of homogeneous objects
`ndarray_deserialization`()	Convert bytes into a numpy ndarray object
`scalar_deserialization`()	Convert bytes into a numbers.Number object
`string_deserialization`()	Convert bytes into a str object

bytes_to_string
from_b64_string
object_deserialization

axis_deserialization() → Axis[source]

Convert bytes into an Axis object

Convert the first bytes into an Axis reading first information about the Axis

Returns: Axis
Return type: the decoded Axis

boolean_deserialization() → bool[source]

Convert bytes into a boolean object

Get first the data type from a string deserialization, then the data length and finally convert this length of bytes into a number (float, int) and cast it to a bool

Returns: bool
Return type: the decoded boolean

static bytes_to_int(bytes_string: bytes) → int[source]: Convert a bytes of length 4 into an integer

static bytes_to_nd_array(data: bytes, dtype: dtype, shape: Tuple[int]) → ndarray[source]

Convert bytes to a ndarray given a certain numpy dtype and shape

Parameters

data (bytes) –
dtype (np.dtype) –
shape (tuple of int) –

Return type

np.ndarray

static bytes_to_scalar(data: bytes, dtype: dtype) → Number[source]

Convert bytes to a scalar given a certain numpy dtype

Parameters

data (bytes) –
dtype (np.dtype) –

Return type

numbers.Number

dte_deserialization() → DataToExport[source]

Convert bytes into a DataToExport object

Convert the first bytes into a DataToExport reading first information about the underlying data

Returns: DataToExport
Return type: the decoded DataToExport

dwa_deserialization() → DataWithAxes[source]

Convert bytes into a DataWithAxes object

Convert the first bytes into a DataWithAxes reading first information about the underlying data

Returns: DataWithAxes
Return type: the decoded DataWithAxes

list_deserialization() → list[source]

Convert bytes into a list of homogeneous objects

Convert the first bytes into a list reading first information about the list elt types, length …

Returns: list
Return type: the decoded list

ndarray_deserialization() → ndarray[source]

Convert bytes into a numpy ndarray object

Convert the first bytes into a ndarray reading first information about the array’s data

Returns: ndarray
Return type: the decoded numpy array

scalar_deserialization() → Number[source]

Convert bytes into a numbers.Number object

Get first the data type from a string deserialization, then the data length and finally convert this length of bytes into a number (float, int)

Returns: numbers.Number
Return type: the decoded number

string_deserialization() → str[source]

Convert bytes into a str object

Convert first the fourth first bytes into an int encoding the length of the string to decode

Returns: str
Return type: the decoded string

class pymodaq.utils.tcp_ip.serializer.Serializer(obj: Optional[Union[int, str, Number, list, ndarray, Axis, DataWithAxes, DataToExport]] = None)[source]

Used to Serialize to bytes python objects, numpy arrays and PyMoDAQ DataWithAxes and DataToExport objects

Methods

`axis_serialization`(axis)	Convert an Axis object into a bytes message together with the info to convert it back
`dte_serialization`(dte)	Convert a DataToExport into a bytes string
`dwa_serialization`(dwa)	Convert a DataWithAxes into a bytes string
`int_to_bytes`(an_integer)	Convert an unsigned integer into a byte array of length 4 in big endian
`list_serialization`(list_object)	Convert a list of objects into a bytes message together with the info to convert it back
`ndarray_serialization`(array)	Convert a ndarray into a bytes message together with the info to convert it back
`object_type_serialization`(obj)	Convert an object type into a bytes message as a string together with the info to convert it back
`scalar_serialization`(scalar)	Convert a scalar into a bytes message together with the info to convert it back
`str_len_to_bytes`(message)	Convert a string and its length to two bytes :param message: the message to convert :type message: str
`string_serialization`(string)	Convert a string into a bytes message together with the info to convert it back
`to_bytes`()	Generic method to obtain the bytes string from various objects

bytes_serialization
str_to_bytes
to_b64_string
type_and_object_serialization

axis_serialization(axis: Axis) → bytes[source]

Convert an Axis object into a bytes message together with the info to convert it back

Parameters: axis (Axis) –
Returns: bytes
Return type: the total bytes message to serialize the Axis

Notes

The bytes sequence is constructed as:

serialize the type: ‘Axis’
serialize the axis label
serialize the axis units
serialize the axis array
serialize the axis
serialize the axis spread_order

dte_serialization(dte: DataToExport) → bytes[source]

Convert a DataToExport into a bytes string

Parameters: dte (DataToExport) –
Returns: bytes
Return type: the total bytes message to serialize the DataToExport

Notes

The bytes sequence is constructed as:

serialize the string type: ‘DataToExport’
serialize the timestamp: float
serialize the name
serialize the list of DataWithAxes

dwa_serialization(dwa: DataWithAxes) → bytes[source]

Convert a DataWithAxes into a bytes string

Parameters: dwa (DataWithAxes) –
Returns: bytes
Return type: the total bytes message to serialize the DataWithAxes

Notes

The bytes sequence is constructed as:

serialize the string type: ‘DataWithAxes’
serialize the timestamp: float
serialize the name
serialize the source enum as a string
serialize the dim enum as a string
serialize the distribution enum as a string
serialize the list of numpy arrays
serialize the list of labels
serialize the origin
serialize the nav_index tuple as a list of int
serialize the list of axis
serialize the errors attributes (None or list(np.ndarray))
serialize the list of names of extra attributes
serialize the extra attributes

static int_to_bytes(an_integer: int) → bytes[source]

Convert an unsigned integer into a byte array of length 4 in big endian

Parameters: an_integer (int) –
Return type: bytearray

list_serialization(list_object: List) → bytes[source]

Convert a list of objects into a bytes message together with the info to convert it back

Parameters: list_object (list) – the list could contains either scalars, strings or ndarrays or Axis objects or DataWithAxis objects module
Returns: bytes
Return type: the total bytes message to serialize the list of objects

Notes

The bytes sequence is constructed as: * the length of the list

Then for each object:

get data type as a string
use the serialization method adapted to each object in the list

ndarray_serialization(array: ndarray) → bytes[source]

Convert a ndarray into a bytes message together with the info to convert it back

Parameters: array (np.ndarray) –
Returns: bytes
Return type: the total bytes message to serialize the scalar

Notes

The bytes sequence is constructed as:

get data type as a string
reshape array as 1D array and get the array dimensionality (len of array’s shape)
convert Data array as bytes
serialize data type
serialize data length
serialize data shape length
serialize all values of the shape as integers converted to bytes
serialize array as bytes

object_type_serialization(obj: Union[Axis, DataToExport, DataWithAxes]) → bytes[source]

Convert an object type into a bytes message as a string together with the info to convert it back

Applies to Data object from the pymodaq.utils.data module

scalar_serialization(scalar: Number) → bytes[source]

Convert a scalar into a bytes message together with the info to convert it back

Parameters: scalar (str) –
Returns: bytes
Return type: the total bytes message to serialize the scalar

classmethod str_len_to_bytes(message: ~typing.Union[str, bytes]) -> (<class 'bytes'>, <class 'bytes'>)[source]

Convert a string and its length to two bytes :param message: the message to convert :type message: str

Returns

bytes (message converted as a byte array)
bytes (length of the message byte array, itself as a byte array of length 4)

string_serialization(string: str) → bytes[source]

Convert a string into a bytes message together with the info to convert it back

Parameters: string (str) –
Returns: bytes
Return type: the total bytes message to serialize the string

to_bytes()[source]

Generic method to obtain the bytes string from various objects

Compatible objects are:

bytes
numbers.Number
str
numpy.ndarray
Axis
DataWithAxes and sub-flavours
DataToExport
list of any objects above

class pymodaq.utils.tcp_ip.serializer.SocketString(bytes_string: bytes)[source]

Mimic the Socket object but actually using a bytes string not a socket connection

Implements a minimal interface of two methods

Parameters: bytes_string (bytes) –

See also

Socket

Methods

`check_received_length`(length)	Make sure all bytes (length) that should be received are received through the socket.
`get_first_nbytes`(length)	Read the first N bytes from the socket

check_received_length(length: int) → bytes[source]

Make sure all bytes (length) that should be received are received through the socket.

Here just read the content of the underlying bytes string

Parameters: length (int) – The number of bytes to be read from the socket
Return type: bytes

get_first_nbytes(length: int) → bytes[source]

Read the first N bytes from the socket

Parameters: length (int) – The number of bytes to be read from the socket
Returns: the read bytes string
Return type: bytes

8.4.2.2. Custom Sockets to implement PyMoDAQ protocol

Created the 26/10/2023

@author: Sebastien Weber

class pymodaq.utils.tcp_ip.mysocket.Socket(socket: Optional[socket] = None)[source]

Custom Socket wrapping the built-in one and added functionalities to make sure message have been sent and received entirely

Attributes

socket

Methods

`check_received_length`(length)	Make sure all bytes (length) that should be received are received through the socket
`check_sended`(data_bytes)	Make sure all bytes are sent through the socket :param data_bytes: :type data_bytes: bytes
`check_sended_with_serializer`(obj)	Convenience function to convert permitted objects to bytes and then use the check_sended method
`get_first_nbytes`(length)	Read the first N bytes from the socket

accept
bind
close
connect
getsockname
listen
recv
send
sendall

check_received_length(length) → bytes[source]

Make sure all bytes (length) that should be received are received through the socket

Parameters: length (int) – The number of bytes to be read from the socket
Return type: bytes

check_sended(data_bytes: bytes)[source]: Make sure all bytes are sent through the socket :param data_bytes: :type data_bytes: bytes

check_sended_with_serializer(obj: object)[source]

Convenience function to convert permitted objects to bytes and then use the check_sended method

For a list of allowed objects, see Serializer.to_bytes()

get_first_nbytes(length: int) → bytes[source]

Read the first N bytes from the socket

Parameters: length (int) – The number of bytes to be read from the socket
Returns: bytes
Return type: the read bytes string

8.4.2.3. Base classes as TCP server and client

Created on Fri Aug 30 12:21:56 2019

@author: Weber

class pymodaq.utils.tcp_ip.tcp_server_client.Grabber(parent: Optional[QObject] = None)[source]

Methods

grab_data()

Do a grab session using 2 profile :

command_tcpip
connect_tcp_ip
process_tcpip_cmds
snapshot

grab_data()[source]

Do a grab session using 2 profile :

if grab pb checked do a continous save and send an “update_channels” thread command and a “grab” too.
if not send a “stop_grab” thread command with settings “main settings-naverage” node value as an attribute.

See also

daq_utils.ThreadCommand, set_enabled_Ini_buttons

class pymodaq.utils.tcp_ip.tcp_server_client.MockServer(client_type='GRABBER')[source]

class pymodaq.utils.tcp_ip.tcp_server_client.TCPClient(ipaddress='192.168.1.62', port=6341, params_state=None, client_type='GRABBER')[source]

PyQt5 object initializing a TCP socket client. Can be used by any module but is a builtin functionality of all actuators and detectors of PyMoDAQ

The module should init TCPClient, move it in a thread and communicate with it using a custom signal connected to TCPClient.queue_command slot. The module should also connect TCPClient.cmd_signal to one of its methods inorder to get info/data back from the client

The client itself communicate with a TCP server, it is best to use a server object subclassing the TCPServer class defined within this python module

Parameters: params_state ((dict) state of the Parameter settings of the module instantiating this client and wishing to) – export its settings to the server. Obtained from param.saveState() where param is an instance of Parameter object, see pyqtgraph.parametertree::Parameter

Methods

`get_data`(message)	param message
`post_init`([extra_commands])	To implement in a real object implementation
`queue_command`([command])	when this TCPClient object is within a thread, the corresponding module communicate with it with signal and slots from module to client: module_signal to queue_command slot from client to module: self.cmd_signal to a module slot
`ready_to_read`()	Do stuff (like read data) when messages arrive through the socket
`ready_to_write`()	Send stuff into the socket
`ready_with_error`()	Error in the socket communication

cmd_signal
data_ready
not_connected
process_error_in_polling
send_data
send_info_string
send_infos_xml

get_data(message: str)[source]

Parameters: message –

post_init(extra_commands=[])[source]: To implement in a real object implementation

queue_command(command=<class 'pymodaq.utils.daq_utils.ThreadCommand'>)[source]: when this TCPClient object is within a thread, the corresponding module communicate with it with signal and slots from module to client: module_signal to queue_command slot from client to module: self.cmd_signal to a module slot

ready_to_read()[source]: Do stuff (like read data) when messages arrive through the socket

ready_to_write()[source]: Send stuff into the socket

ready_with_error()[source]: Error in the socket communication

class pymodaq.utils.tcp_ip.tcp_server_client.TCPServer(client_type='GRABBER')[source]

Abstract class to be used as inherited by DAQ_Viewer_TCP or DAQ_Move_TCP

Methods

`close_server`()	close the current opened server.
`find_socket_type_within_connected_clients`(sock)	Find a socket type from a connected client with socket content corresponding.
`find_socket_within_connected_clients`(client_type)	Find a socket from a connected client with socket type corresponding.
`listen_client`()	Server function.
`print_status`(status)	Print the given status.
`process_cmds`(command[, command_sock])	Process the given command.
`read_info`([sock, test_info, test_value])	if the client is not from PyMoDAQ it can use this method to display some info into the server widget
`select`(rlist[, wlist, xlist, timeout])	Implements the select method, https://docs.python.org/3/library/select.html :param rlist: :type rlist: (list) wait until ready for reading :param wlist: :type wlist: (list) wait until ready for writing :param xlist: :type xlist: (list) wait for an “exceptional condition” :param timeout: When the timeout argument is omitted the function blocks until at least one file descriptor is ready. A time-out value of zero specifies a poll and never blocks. :type timeout: (float) optional timeout argument specifies a time-out as a floating point number in seconds.
`send_command`(sock[, command])	Send one of the message contained in self.message_list toward a socket with identity socket_type.
`timerEvent`(event)	Called by set timers.

command_done
command_to_from_client
emit_status
init_server
read_data
read_info_xml
read_infos
remove_client
send_data
set_connected_clients_table

close_server()[source]: close the current opened server. Update the settings tree consequently.

See also

set_connected_clients_table, daq_utils.ThreadCommand

find_socket_type_within_connected_clients(sock)[source]

Find a socket type from a connected client with socket content corresponding.

Parameters	Type	Description
sock	???	The socket content corresponding.

Returns: the socket dictionnary
Return type: dictionnary

find_socket_within_connected_clients(client_type) → Socket[source]

Find a socket from a connected client with socket type corresponding.

Parameters	Type	Description
client_type	string	The corresponding client type

Returns: the socket dictionnary
Return type: dictionnary

listen_client()[source]: Server function. Used to connect or listen incoming message from a client.

print_status(status)[source]

Print the given status.

Parameters	Type	Description
status	string list	a string list representing the status socket

process_cmds(command, command_sock=None)[source]: Process the given command.

read_info(sock: Optional[Socket] = None, test_info='an_info', test_value='')[source]: if the client is not from PyMoDAQ it can use this method to display some info into the server widget

select(rlist, wlist=[], xlist=[], timeout=0)[source]

Implements the select method, https://docs.python.org/3/library/select.html :param rlist: :type rlist: (list) wait until ready for reading :param wlist: :type wlist: (list) wait until ready for writing :param xlist: :type xlist: (list) wait for an “exceptional condition” :param timeout: When the timeout argument is omitted the function blocks until at least one file descriptor is ready.

A time-out value of zero specifies a poll and never blocks.

Returns

list (readable sockets)
list (writable sockets)
list (sockets with error pending)

send_command(sock: Socket, command='move_at')[source]

Send one of the message contained in self.message_list toward a socket with identity socket_type. First send the length of the command with 4bytes.

Parameters	Type	Description
sock	???	The current socket
command	string	The command as a string

See also

utility_classes.DAQ_Viewer_base.emit_status, daq_utils.ThreadCommand, message_to_bytes

set_connected_clients_table()[source]

timerEvent(event)[source]

Called by set timers. If the process is free, start the listen_client function.

Parameters	Type	Description
event	QTimerEvent object	Containing id from timer issuing this event

See also

listen_client