// windows: cl sockettest.cpp ws2_32.lib /Ox
// freebsd: g++ sockettest.cpp -o sockettest -O3

#ifdef _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#include <windows.h>
#else
#include <sys/socket.h>
#include <netinet/in.h> //IPPROTO_TCP
#include <netdb.h> //getaddrinfo()
#include <unistd.h> //close()
#include <sys/time.h> //timeval, gettimeofday()
#define SOCKET int
#define SOCKET_ERROR (-1)
#define closesocket(x) close(x)
#endif
#include <stdio.h> //NULL, printf()
#include <string.h> //memset()
#include <math.h> //pow()


#ifdef _WIN32
class WSAHelper
{
public:
	WSAHelper()
	{ 
		WSAData data;
		WSAStartup(MAKEWORD(2,2), &data);
	}

	~WSAHelper()
	{
		WSACleanup();
	}
};
WSAHelper g_wsah;
#endif


unsigned int tick(void)
{
#ifdef _WIN32
	return GetTickCount();
#else
	struct timeval tval;
	gettimeofday(&tval, NULL);
	return tval.tv_sec * 1000 + tval.tv_usec / 1000;
#endif
}


// use netcat on server side
// nc -l -k 5555 > /dev/null
const char* server = "example.org";
const char* port = "5555";
int nIterations = 8;
int nSends = 2048;
int nBytes = 512;


int main(int argc, char* argv[])
{
	if( argc > 2 )
	{
		server = argv[1];
		port = argv[2];
	}

	// just for informative purposes	
	SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	int default_bufsize;
	socklen_t slen = sizeof(default_bufsize);
	int ret2 = getsockopt(s, SOL_SOCKET, SO_SNDBUF, (char*)&default_bufsize, &slen);
	printf("Default send buffer size is %d.\n", default_bufsize);
	closesocket(s);

	for( int r = 0; r < nIterations; ++r )
	{                  
	printf("Iteration %d...", r);
	scanf("%*c");

	SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

	int bufsize = 8192 * pow(2,(float)r);
	int ret1 = setsockopt(s, SOL_SOCKET, SO_SNDBUF, (char*)&bufsize, sizeof(bufsize));

	struct linger l;
	l.l_onoff = 1; // enabled
	l.l_linger = 10; // seconds
	setsockopt(s, SOL_SOCKET, SO_LINGER, (char*)&l, sizeof(l));

	addrinfo* ai;
	getaddrinfo(server, port, NULL, &ai);

	connect(s, ai->ai_addr, ai->ai_addrlen);

	char* buf = new char[nBytes];
	memset(buf, '\0', nBytes);

	time_t start = tick();

	for( int i = 0; i < nSends; ++i )
		send(s, buf, nBytes, 0);

	closesocket(s);

	time_t end = tick();

	delete[] buf;

	printf("%d bytes at %d bufsize in %d ms.\n", nSends*nBytes, bufsize, end-start);

	}

	return 0;
}