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/*
* Copyright (C) 2017 Tommi Maekitalo
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* As a special exception, you may use this file as part of a free
* software library without restriction. Specifically, if other files
* instantiate templates or use macros or inline functions from this
* file, or you compile this file and link it with other files to
* produce an executable, this file does not by itself cause the
* resulting executable to be covered by the GNU General Public
* License. This exception does not however invalidate any other
* reasons why the executable file might be covered by the GNU Library
* General Public License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* This is a tcp server, which demonstrate non blocking I/O on stdin.
*
* The class cxxtools::Cin is a cxxtools::IStream, which is a std::istream
* with non blocking I/O.
* The server accepts connections on a port (default is 1234, can be changed
* with the command line optin -p). It reads from stdin and sends everything
* to all connected clients.
*
* To try it out, start the server in one terminal and execute e.g. netcat,
* which is often installed, on one or more other terminals using
* `nc localhost 1234`. Everything you enter now on the keyboard to `insrv`
* is echoed to the nc processes.
*
*/
#include <iostream>
#include <cxxtools/application.h>
#include <cxxtools/stdstream.h>
#include <cxxtools/net/tcpserver.h>
#include <cxxtools/net/tcpstream.h>
#include <cxxtools/arg.h>
#include <cxxtools/log.h>
#include <vector>
log_define("insrv")
class Insrv : public cxxtools::Application
{
cxxtools::Cin in;
cxxtools::net::TcpServer srv;
typedef std::vector<cxxtools::net::TcpStream*> Clients;
Clients _clients;
void onInput(cxxtools::IStream& s);
void onOutput(cxxtools::net::TcpStream& s);
void onConnect(cxxtools::net::TcpServer& srv);
void onClosed(cxxtools::net::TcpStream& s);
public:
Insrv(int& argc, char* argv[]);
~Insrv();
};
Insrv::Insrv(int& argc, char* argv[])
: cxxtools::Application(argc, argv)
{
cxxtools::Arg<std::string> ip(argc, argv, 'i');
cxxtools::Arg<unsigned short> port(argc, argv, 'p', 1234);
// Attach our stdin device to the event loop of the application
// and inform that we want to read from there.
in.setSelector(loop());
in.beginRead();
cxxtools::connect(in.inputReady, *this, &Insrv::onInput);
// Initialize our tcp server class.
srv.listen(ip, port);
srv.setSelector(loop());
cxxtools::connect(srv.connectionPending, *this, &Insrv::onConnect);
}
Insrv::~Insrv()
{
for (Clients::iterator it = _clients.begin(); it != _clients.end(); ++it)
delete *it;
}
void Insrv::onInput(cxxtools::IStream& s)
{
try
{
// Finalize reading, which was started with beginRead.
// This does the actual read and fills the input buffer.
s.endRead();
}
catch (const std::exception& e)
{
log_info("read failed with error: " << e.what());
loop().exit();
return;
}
log_debug("onInput; in_avail=" << s.in_avail());
if (!s.good())
{
log_debug("exit loop");
loop().exit();
return;
}
char buffer[8192];
while (s.in_avail())
{
unsigned count = s.readsome(buffer, sizeof(buffer));
// For each client we put the data to the output buffer and initiate writing.
for (Clients::iterator it = _clients.begin(); it != _clients.end(); ++it)
{
log_debug("write " << count << " bytes to client " << static_cast<void*>(*it));
(*it)->write(buffer, count);
(*it)->beginWrite();
}
}
log_debug("read");
s.beginRead();
}
void Insrv::onOutput(cxxtools::net::TcpStream& s)
{
try
{
// This signals that the client is ready to receive data without blocking.
// We finish the write operation and if there is more to send, we initiate
// the next write operation, so that we are signalled, when the device
// is ready to receive more data.
log_trace("endWrite " << static_cast<void*>(&s));
s.endWrite();
if (s.out_avail() > 0)
{
log_debug("beginWrite " << static_cast<void*>(&s));
s.beginWrite();
}
}
catch (const std::exception& e)
{
onClosed(s);
}
}
void Insrv::onClosed(cxxtools::net::TcpStream& s)
{
log_debug("client disconnected " << static_cast<void*>(&s));
for (Clients::iterator it = _clients.begin(); it != _clients.end(); ++it)
{
if ((*it) == &s)
{
log_debug("remove client " << static_cast<void*>(*it));
delete *it;
_clients.erase(it);
break;
}
}
}
void Insrv::onConnect(cxxtools::net::TcpServer& srv)
{
// A new client is detected. We create a new client class
// and connect the needed signals.
// Close is either signaled with a exception when a I/O operation is
// finished using `endRead` or `endWrite` or if a close is detected in the
// event loop while no I/O operation is pending the signal `closed` is
// sent.
cxxtools::net::TcpStream* cli = new cxxtools::net::TcpStream(srv);
log_debug("new client connected " << static_cast<void*>(cli));
_clients.push_back(cli);
cli->setSelector(loop());
cxxtools::connect(cli->outputReady, *this, &Insrv::onOutput);
cxxtools::connect(cli->closed, *this, &Insrv::onClosed);
}
int main(int argc, char* argv[])
{
try
{
log_init();
Insrv app(argc, argv);
app.run();
}
catch (const std::exception& e)
{
std::cerr << e.what() << std::endl;
}
}
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