Classes related to interprocess communications. More...

Classes
class	CommandClient
	Class to be used for sending commands. More...

class	CommandServer
	`QTcpServer` class used to receive commands and execute them. More...

class	CommandThread
	`QThread` class used to receive commands, try to execute and respond to them. More...

Functions
def	checkIPIsValid (ip)
	Method used to check a selected IP is possible to use with a Qt's QHostAddress. More...

def	startServer (addr, port)
	Method used to try to start a `CommandServer` at a valid IP address and port. More...

def	sendClientCommand (host, port, cmd, wait_time=WAIT_TIME_MS)
	Method to be used for sending commands. More...

Variables
int	SIZEOF_UINT16 = 2
	Size of uint16 in bytes used to leave space at the beginning of each message to specify tcp message length (maximal length is 65535 bytes). More...

int	SERVER_ERROR_INVALID_ADDRESS = 1
	Error code used in startServer() when trying to connect CommandServer to an invalid address. More...

int	SERVER_ERROR_PORT_OCCUPIED = 2
	Error code used in startServer() when trying to connect CommandServer to an occupied port. More...

int	WAIT_TIME_MS = 30000
	Time to wait in milliseconds - used to wait for incoming message etc. More...

string	COMMAND_EXECUTED_CONFIRMATION_MESSAGE = "Command executed successfully"
	Message send from a `CommandServer` to a `CommandClient.sendCommand()` or `sendClientCommand()` after successful execution of a command. More...

int	CLIENT_COMMAND_EXECUTED = 0
	`CommandClient.sendCommand()` or `sendClientCommand()` return value after confirmation of successful command execution. More...

int	CLIENT_COMMAND_FAILED = 1
	`CommandClient.sendCommand()` or `sendClientCommand()` return value if command execution failed (invalid command string). More...

int	CLIENT_ERROR_RESPONSE_NOT_COMPLETE = 2
	`CommandClient.sendCommand()` or `sendClientCommand()` error code to signal that response was no received complete. More...

int	CLIENT_ERROR_NO_RESPONSE = 3
	`CommandClient.sendCommand()` or `sendClientCommand()` error code to signal that no response from `CommandServer` was received. More...

int	CLIENT_ERROR_BLOCK_NOT_WRITTEN = 4
	`CommandClient.sendCommand()` or `sendClientCommand()` error code to signal that message block was not written to a TCP socket. More...

int	CLIENT_ERROR_NO_CONNECTION = 5
	`CommandClient.sendCommand()` or `sendClientCommand()` error code to signal that connection a host `CommandServer` was not established. More...

Detailed Description

Classes related to interprocess communications.

The Classes in this module...

Function Documentation

◆ checkIPIsValid()

def communication.checkIPIsValid ( ip )

Method used to check a selected IP is possible to use with a Qt's QHostAddress.

The IP can be either IPv4 address or *"localhost"* string with possible capital letters anywhere. IPv6 is not supported for now.

Parameters

ip	A str with an IP address selected.

Definition at line 244 of file communication.py.

 def checkIPIsValid(ip):
     if ip.upper() == "LOCALHOST":
         return True
 
     numbers = ip.split(".")
     if len(numbers) == 4:
         if all([(0 <= int(num) <= 255) for num in numbers]):
             return True
 
     return False
 
 

◆ sendClientCommand()

def communication.sendClientCommand	(	host,
		port,
		cmd,
		wait_time = `WAIT_TIME_MS`
	)

Method to be used for sending commands.

This method is an alternative to using CommandClient. It does not print any logs, just returns a value saying how the execution went.

To send a command using this method do: sendClientCommand("127.0.0.1",54333, "FreeCAD.Console.PrintWarning('Hello World\\n')")

Parameters

cmd	A str command to be executed.
host	A QtHostAddress to the `CommandServer`.
port	An int of port at which `CommandServer` is listening.
wait_time	An int setting milliseconds to wait for connection or message.

Returns: CLIENT_COMMAND_EXECUTED if all went great and command was executed. CLIENT_COMMAND_FAILED if cmd execution failed. CLIENT_ERROR_RESPONSE_NOT_COMPLETE if a response received was incomplete. CLIENT_ERROR_NO_RESPONSE if there was no response within WAIT_TIME_MS. CLIENT_ERROR_BLOCK_NOT_WRITTEN if communication failed during sending. CLIENT_ERROR_NO_CONNECTION if no connection to a host was established.

Definition at line 483 of file communication.py.

 def sendClientCommand(host, port, cmd, wait_time=WAIT_TIME_MS):
     # Try to connect to a host server
     tcpSocket = QTcpSocket()
     tcpSocket.connectToHost(host, port, QIODevice.ReadWrite)
     if not tcpSocket.waitForConnected(msecs=wait_time):
         return CLIENT_ERROR_NO_CONNECTION
 
     # Prepare a command message to be sent
     block = QByteArray(
             len(cmd.encode("UTF-8")).to_bytes(2, byteorder='big')
             + cmd.encode("UTF-8"))
     outstr = QDataStream(block, QIODevice.WriteOnly)
     outstr.setVersion(QDataStream.Qt_4_0)
     tcpSocket.write(block)
 
     # Try to send the message
     if not tcpSocket.waitForBytesWritten(msecs=wait_time):
         return CLIENT_ERROR_BLOCK_NOT_WRITTEN
 
     # Wait for a response from the host server
     if not tcpSocket.waitForReadyRead(msecs=wait_time):
         return CLIENT_ERROR_NO_RESPONSE
 
     # Try to read the response
     instr = QDataStream(tcpSocket)
     instr.setVersion(QDataStream.Qt_4_0)
     blockSize = 0
     if blockSize == 0:
         if tcpSocket.bytesAvailable() < 2:
             return CLIENT_ERROR_RESPONSE_NOT_COMPLETE
         blockSize = instr.readUInt16()
     if tcpSocket.bytesAvailable() < blockSize:
         return CLIENT_ERROR_RESPONSE_NOT_COMPLETE
 
     # Wait until the host server terminates the connection
     tcpSocket.waitForDisconnected()
 
     # Return value representing a command execution status
     if instr.readRawData(blockSize).decode("UTF-8") \
             == COMMAND_EXECUTED_CONFIRMATION_MESSAGE:
         return CLIENT_COMMAND_EXECUTED
     else:
         return CLIENT_COMMAND_FAILED

◆ startServer()

def communication.startServer	(	addr,
		port
	)

Method used to try to start a CommandServer at a valid IP address and port.

This method checks that a chosen addr is valid IP address to be used to create Qt's QHostAddress using checkIPIsValid(). If the IP address is valid, then a CommandServer instance is created and tried to be made listen at selected addr and port. If it fails, then the used port had to be occupied.

Parameters

addr	A str with a valid IPv4 Address or "localhost".
port	An int selecting a port to be used for the `CommandServer`.

Returns: An integer error code signifying that and error occurred(either ERROR_INVALID ADDRESS or ERROR_PORT_OCCUPIED) or a CommnadServer instance if everything went hunky-dory.

Definition at line 273 of file communication.py.

 def startServer(addr, port):
 
     if not checkIPIsValid(addr):
         return SERVER_ERROR_INVALID_ADDRESS
 
     if addr.upper() == "LOCALHOST":
         addr = QHostAddress(QHostAddress.LocalHost)
     else:
         addr = QHostAddress(addr)
 
     server = CommandServer()
     if not server.listen(addr, port):
         FreeCAD.Console.PrintLog("Unable to start the server: %s.\n"
                                  % server.errorString())
         return SERVER_ERROR_PORT_OCCUPIED
 
     else:
         FreeCAD.Console.PrintLog("The server is running on address %s"
                                  % server.serverAddress().toString()
                                  + " and port %d.\n" % server.serverPort())
         return server
 
 

Variable Documentation

◆ CLIENT_COMMAND_EXECUTED

int communication.CLIENT_COMMAND_EXECUTED = 0

CommandClient.sendCommand() or sendClientCommand() return value after confirmation of successful command execution.

Definition at line 65 of file communication.py.

◆ CLIENT_COMMAND_FAILED

int communication.CLIENT_COMMAND_FAILED = 1

CommandClient.sendCommand() or sendClientCommand() return value if command execution failed (invalid command string).

Definition at line 69 of file communication.py.

◆ CLIENT_ERROR_BLOCK_NOT_WRITTEN

int communication.CLIENT_ERROR_BLOCK_NOT_WRITTEN = 4

CommandClient.sendCommand() or sendClientCommand() error code to signal that message block was not written to a TCP socket.

Definition at line 81 of file communication.py.

◆ CLIENT_ERROR_NO_CONNECTION

int communication.CLIENT_ERROR_NO_CONNECTION = 5

CommandClient.sendCommand() or sendClientCommand() error code to signal that connection a host CommandServer was not established.

Definition at line 85 of file communication.py.

◆ CLIENT_ERROR_NO_RESPONSE

int communication.CLIENT_ERROR_NO_RESPONSE = 3

CommandClient.sendCommand() or sendClientCommand() error code to signal that no response from CommandServer was received.

Definition at line 77 of file communication.py.

◆ CLIENT_ERROR_RESPONSE_NOT_COMPLETE

int communication.CLIENT_ERROR_RESPONSE_NOT_COMPLETE = 2

CommandClient.sendCommand() or sendClientCommand() error code to signal that response was no received complete.

Definition at line 73 of file communication.py.

◆ COMMAND_EXECUTED_CONFIRMATION_MESSAGE

string communication.COMMAND_EXECUTED_CONFIRMATION_MESSAGE = "Command executed successfully"

Message send from a CommandServer to a CommandClient.sendCommand() or sendClientCommand() after successful execution of a command.

Definition at line 61 of file communication.py.

◆ SERVER_ERROR_INVALID_ADDRESS

int communication.SERVER_ERROR_INVALID_ADDRESS = 1

Error code used in startServer() when trying to connect CommandServer to an invalid address.

Definition at line 50 of file communication.py.

◆ SERVER_ERROR_PORT_OCCUPIED

int communication.SERVER_ERROR_PORT_OCCUPIED = 2

Error code used in startServer() when trying to connect CommandServer to an occupied port.

Definition at line 54 of file communication.py.

◆ SIZEOF_UINT16

int communication.SIZEOF_UINT16 = 2

Size of uint16 in bytes used to leave space at the beginning of each message to specify tcp message length (maximal length is 65535 bytes).

Definition at line 46 of file communication.py.

◆ WAIT_TIME_MS

int communication.WAIT_TIME_MS = 30000

Time to wait in milliseconds - used to wait for incoming message etc.

Definition at line 57 of file communication.py.

Classes

Functions

Variables

Detailed Description

Function Documentation

◆ checkIPIsValid()

◆ sendClientCommand()

◆ startServer()

Variable Documentation

◆ CLIENT_COMMAND_EXECUTED

◆ CLIENT_COMMAND_FAILED

◆ CLIENT_ERROR_BLOCK_NOT_WRITTEN

◆ CLIENT_ERROR_NO_CONNECTION

◆ CLIENT_ERROR_NO_RESPONSE

◆ CLIENT_ERROR_RESPONSE_NOT_COMPLETE

◆ COMMAND_EXECUTED_CONFIRMATION_MESSAGE

◆ SERVER_ERROR_INVALID_ADDRESS

◆ SERVER_ERROR_PORT_OCCUPIED

◆ SIZEOF_UINT16

◆ WAIT_TIME_MS