Server¶

class Server(*args, **kwargs)¶

Bases: Network

This class represents a Transmission Control Protocol (TCP) server.

TCP provides reliable, ordered delivery of a stream of bytes from a program on one computer to another program on another computer.

Example of server’s code, receiving and sending basic message. It corresponds to the client used in the first example of vpClient class’ documentation.

#include <iostream>
#include <visp3/core/vpServer.h>

int main(int argc,const char** argv)
{
  int port = 35000;
  vpServer serv(port); //Launch the server on localhost
  serv.start();

  bool run = true;
  int val;

  while(run){
    serv.checkForConnections();

    if(serv.getNumberOfClients() > 0)
    {
      // Receiving a value from the first client
      if(serv.receive(&val) != sizeof(int))
        std::cout << "Error while receiving" << std::endl;
      else
        std::cout << "Received : " << val << std::endl;

      val = val+1;
      // Sending the new value to the first client
      if(serv.send(&val) != sizeof(int))
        std::cout << "Error while sending" << std::endl;
      else
        std::cout << "Sending : " << val << std::endl;
    }
  }

  return 0;
}

Example of server’s code, receiving a vpImage on request form. It correspond to the client used in the second example of vpClient class’ documentation.

#include <visp3/core/vpServer.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayX.h>

#include "vpRequestImage.h" //See vpRequest class documentation

int main(int argc,const char** argv)
{
  int port = 35000;

  std::cout << "Port: " << port << std::endl;
  vpServer serv(port);
  serv.start();

#if defined(VISP_HAVE_X11)
  vpDisplayX display;
#elif defined(VISP_HAVE_GDI) //Win32
  vpDisplayGDI display;
#endif

  vpImage<unsigned char> I;

  vpRequestImage reqImage(&I);
  serv.addDecodingRequest(&reqImage);

  bool run = true;

  while(run){
    serv.checkForConnections();

    if(serv.getNumberOfClients() > 0)
    {
      int index = serv.receiveAndDecodeRequestOnce();
      std::string id = serv.getRequestIdFromIndex(index);

      if(id == reqImage.getId())
      {
#if defined(VISP_HAVE_X11) || defined(VISP_HAVE_GDI)
        if (! display.isInitialised() )
          display.init(I, -1, -1, "Remote display");
#endif

        vpDisplay::display(I) ;
        vpDisplay::flush(I);

        // A click in the viewer to exit
        if ( vpDisplay::getClick(I, false) )
          run = false;
      }
    }
  }

  return 0;
}

Note

See vpClient

Note

See vpRequest

Note

See vpNetwork

Overloaded function.

__init__(self: visp._visp.core.Server) -> None

Construct a server on the machine launching it.

__init__(self: visp._visp.core.Server, port: int) -> None
__init__(self: visp._visp.core.Server, adress_serv: str, port_serv: int) -> None

Construct a server on the machine at a given adress, with a specified port.

Parameters:

adress_serv: server’s adress.
port_serv: server’s port.

Methods

`__init__`	Overloaded function.
`checkForConnections`	Check if a client has connected or deconnected the server
`getMaxNumberOfClients`	Get the maximum number of clients that can be connected to the server.
`getNumberOfClients`	Get the number of clients connected to the server.
`isStarted`	Check if the server is started.
`print`	Overloaded function.
`setMaxNumberOfClients`	Set the maximum number of clients that can be connected to the server.
`start`	Enable the server to wait for clients (on the limit of the maximum limit).

Inherited Methods

`removeDecodingRequest`	Delete a decoding request from the emitter.
`sendRequestTo`	Send a request to a specific receptor.
`sendRequest`	Send a request to the first receptor in the list.
`setTimeoutSec`	Change the time the emitter spend to check if he receives a message from a receptor.
`receiveAndDecodeRequestFrom`	Receives and decode requests, from a specific emitter, until there is request to receive.
`receiveAndDecodeRequestOnceFrom`	Receives a message once (in the limit of the Maximum message size value), from a specific emitter.
`sendAndEncodeRequestTo`	Send and encode a request to a specific receptor.
`receiveRequest`	Receive requests until there is requests to receive.
`setMaxSizeReceivedMessage`	Change the maximum size that the emitter can receive (in request mode).
`receiveAndDecodeRequestOnce`	Receives a message once (in the limit of the Maximum message size value).
`setVerbose`	Set the verbose mode.
`receiveRequestOnceFrom`	Receives a message once (in the limit of the Maximum message size value), from a specific emitter.
`setTimeoutUSec`	Change the time the emitter spend to check if he receives a message from a receptor.
`receiveRequestFrom`	Receives requests, from a specific emitter, until there is request to receive.
`sendAndEncodeRequest`	Send and encode a request to the first receptor in the list.
`getReceptorIndex`	Get the receptor index from its name.
`receiveAndDecodeRequest`	Receives and decode requests until there is requests to receive.
`getMaxSizeReceivedMessage`	Get the maximum size that the emitter can receive (in request mode).
`getRequestIdFromIndex`	Get the Id of the request at the index ind.
`receiveRequestOnce`	Receives a message once (in the limit of the Maximum message size value).

Operators

`__doc__`
`__init__`	Overloaded function.
`__module__`

Attributes

`__annotations__`

__init__(*args, **kwargs)¶

Overloaded function.

__init__(self: visp._visp.core.Server) -> None

Construct a server on the machine launching it.

__init__(self: visp._visp.core.Server, port: int) -> None
__init__(self: visp._visp.core.Server, adress_serv: str, port_serv: int) -> None

Construct a server on the machine at a given adress, with a specified port.

Parameters:

adress_serv: server’s adress.
port_serv: server’s port.

checkForConnections(self) → bool¶

Check if a client has connected or deconnected the server

Returns:: True if a client connected or deconnected, false otherwise OR server not started yet.

getMaxNumberOfClients(self) → int¶

Get the maximum number of clients that can be connected to the server.

Returns:: Maximum number of clients.

getMaxSizeReceivedMessage(self) → int¶

Get the maximum size that the emitter can receive (in request mode).

Returns:: Acutal max size value.

getNumberOfClients(self) → int¶

Get the number of clients connected to the server.

Returns:: Number of clients connected.

getReceptorIndex(self, name: str) → int¶

Get the receptor index from its name. The name can be either the IP, or its name on the network.

Parameters:

name: str¶: Name of the receptor.

Returns:

Index of the receptor, or -1 if an error occurs.

getRequestIdFromIndex(self, ind: int) → str¶

Get the Id of the request at the index ind.

Parameters:

ind: int¶: Index of the request.

Returns:

Id of the request.

isStarted(self) → bool¶

Check if the server is started.

Returns:: True if the server is started, false otherwise.

print(*args, **kwargs)¶

Overloaded function.

print(self: visp._visp.core.Server) -> None

Print the connected clients.

print(self: visp._visp.core.Network, id: str = ) -> None

Print the receptors.

Parameters:

id: Message to display before the receptor’s index.

receiveAndDecodeRequest(self) → list[int]¶: Receives and decode requests until there is requests to receive.

Warning

Requests will be received but not decoded.

Note

See vpNetwork::receive()

Note

See vpNetwork::receiveRequestFrom()

Note

See vpNetwork::receiveRequestOnce()

Note

See vpNetwork::receiveRequestOnceFrom()

Note

See vpNetwork::receiveAndDecodeRequest()

Note

See vpNetwork::receiveAndDecodeRequestFrom()

Note

See vpNetwork::receiveAndDecodeRequestOnce()

Note

See vpNetwork::receiveAndDecodeRequestOnceFrom()

receiveAndDecodeRequestFrom(self, receptorEmitting: int) → list[int]¶

Receives and decode requests, from a specific emitter, until there is request to receive.

Warning

Requests will be received but not decoded.

Note

See vpNetwork::receive()

Note

See vpNetwork::receiveRequest()

Note

See vpNetwork::receiveRequestOnce()

Note

See vpNetwork::receiveRequestOnceFrom()

Note

See vpNetwork::receiveAndDecodeRequest()

Note

See vpNetwork::receiveAndDecodeRequestFrom()

Note

See vpNetwork::receiveAndDecodeRequestOnce()

Note

See vpNetwork::receiveAndDecodeRequestOnceFrom()

Parameters:

receptorEmitting: int¶: Index of the receptor emitting the message

receiveAndDecodeRequestOnce(self) → int¶

Receives a message once (in the limit of the Maximum message size value). This message can represent an entire request or not. Several calls to this function might be necessary to get the entire request. If it represents an entire request, it decodes the request.

Returns:: The number of bytes received, -1 if an error occurred.

receiveAndDecodeRequestOnceFrom(self, receptorEmitting: int) → int¶

Receives a message once (in the limit of the Maximum message size value), from a specific emitter. This message can represent an entire request or not. Several calls to this function might be necessary to get the entire request. If it represents an entire request, it decodes the request.

Parameters:

receptorEmitting: int¶: Index of the receptor emitting the message.

Returns:

The number of bytes received, -1 if an error occurred.

receiveRequest(self) → list[int]¶: Receive requests until there is requests to receive.

Warning

Requests will be received but not decoded.

Note

See vpNetwork::receive()

Note

See vpNetwork::receiveRequestFrom()

Note

See vpNetwork::receiveRequestOnce()

Note

See vpNetwork::receiveRequestOnceFrom()

Note

See vpNetwork::receiveAndDecodeRequest()

Note

See vpNetwork::receiveAndDecodeRequestFrom()

Note

See vpNetwork::receiveAndDecodeRequestOnce()

Note

See vpNetwork::receiveAndDecodeRequestOnceFrom()

receiveRequestFrom(self, receptorEmitting: int) → list[int]¶

Receives requests, from a specific emitter, until there is request to receive.

Warning

Requests will be received but not decoded.

Note

See vpNetwork::receive()

Note

See vpNetwork::receiveRequest()

Note

See vpNetwork::receiveRequestOnce()

Note

See vpNetwork::receiveRequestOnceFrom()

Note

See vpNetwork::receiveAndDecodeRequest()

Note

See vpNetwork::receiveAndDecodeRequestFrom()

Note

See vpNetwork::receiveAndDecodeRequestOnce()

Note

See vpNetwork::receiveAndDecodeRequestOnceFrom()

Parameters:

receptorEmitting: int¶: Index of the receptor emitting the message

receiveRequestOnce(self) → int¶

Returns:: The number of bytes received, -1 if an error occurred.

receiveRequestOnceFrom(self, receptorEmitting: int) → int¶

Parameters:

receptorEmitting: int¶: Index of the receptor emitting the message.

Returns:

The number of bytes received, -1 if an error occurred.

removeDecodingRequest(self, arg0: str) → None¶: Delete a decoding request from the emitter.

Note

See vpNetwork::addDecodingRequest()

sendAndEncodeRequest(self, req: visp._visp.core.Request) → int¶

Send and encode a request to the first receptor in the list.

Parameters:

req: visp._visp.core.Request¶: Request to send.

Returns:

The number of bytes that have been sent, -1 if an error occurred.

sendAndEncodeRequestTo(self, req: visp._visp.core.Request, dest: int) → int¶

Send and encode a request to a specific receptor.

Parameters:

req: visp._visp.core.Request¶: Request to send.
dest: int¶: Index of the receptor receiving the request.

Returns:

The number of bytes that have been sent, -1 if an error occurred.

sendRequest(self, req: visp._visp.core.Request) → int¶

Send a request to the first receptor in the list.

Parameters:

req: visp._visp.core.Request¶: Request to send.

Returns:

The number of bytes that have been sent, -1 if an error occurred.

sendRequestTo(self, req: visp._visp.core.Request, dest: int) → int¶

Send a request to a specific receptor.

Parameters:

req: visp._visp.core.Request¶: Request to send.
dest: int¶: Index of the receptor receiving the request.

Returns:

The number of bytes that have been sent, -1 if an error occurred.

setMaxNumberOfClients(self, l: int) → None¶

Set the maximum number of clients that can be connected to the server.

Note

See vpServer::getMaxNumberOfClients()

Parameters:

l: int¶: Maximum number of clients.

setMaxSizeReceivedMessage(self, s: int) → None¶

Change the maximum size that the emitter can receive (in request mode).

Note

See vpNetwork::getMaxSizeReceivedMessage()

Parameters:

s: int¶: new maximum size value.

setTimeoutSec(self, sec: int) → None¶

Change the time the emitter spend to check if he receives a message from a receptor. Initially this value is set to 10usec.

Note

See vpNetwork::setTimeoutUSec()

Parameters:

sec: int¶: new value in second.

setTimeoutUSec(self, usec: int) → None¶

Change the time the emitter spend to check if he receives a message from a receptor. Initially this value is set to 10usec.

Note

See vpNetwork::setTimeoutSec()

Parameters:

usec: int¶: new value in micro second.

setVerbose(self, mode: bool) → None¶

Set the verbose mode.

Parameters:

mode: bool¶: Change the verbose mode. True to turn on, False to turn off.

start(self) → bool¶

Enable the server to wait for clients (on the limit of the maximum limit).

Returns:: True if the server has started, false otherwise.