msgpack_tcp.cc

#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <exception>
#include <string>

int connect_tcp(std::string host, std::string port) {
  struct addrinfo hints;
  struct addrinfo *result, *rp;
  int sock;
  int r;
    
  memset(&hints, 0, sizeof(struct addrinfo));
  hints.ai_family = AF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_flags = 0;
  hints.ai_protocol = 0;
    
  if (0 != (r = getaddrinfo(host.c_str(), port.c_str(),
                            &hints, &result))) {
    std::string errmsg(gai_strerror(r));
    throw std::runtime_error("getaddrinfo error: " + errmsg);
  }
    
  for (rp = result; rp != NULL; rp = rp->ai_next) {
    sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
    if (sock == -1) {
      continue;
    }
    
    if (connect(sock, rp->ai_addr, rp->ai_addrlen) != -1) {
      char buf[INET6_ADDRSTRLEN];
      struct sockaddr_in *addr_in = (struct sockaddr_in *) rp->ai_addr;
      inet_ntop(rp->ai_family, &addr_in->sin_addr.s_addr, buf,
                rp->ai_addrlen);
    
      break;
    }
  }
    
  if (rp == NULL) {
    throw std::runtime_error("no avaiable address for " + host);
  }
  freeaddrinfo(result);
  return sock;
}
    
#include <msgpack.hpp>
#include <sys/time.h>

void send_msg(int sock) {
  struct timeval tv;
  msgpack::sbuffer buf;
  msgpack::packer <msgpack::sbuffer> pk (&buf);
    
  std::string tag("test.tag");
  std::string k1("a"), k2("b");
  gettimeofday(&tv, NULL);
  pk.pack_array(2);   // [_, _]
  pk.pack(tag);       // ["test.tag", _]
  pk.pack_array(1);   // ["test.tag", [_]]
  pk.pack_array(2);   // ["test.tag", [[_, _]]]
  pk.pack(tv.tv_sec); // ["test.tag", [[123400xxx, _]]]
  pk.pack_map(2);     // ["test.tag", [[123400xxx, {}]]]
  pk.pack(k1); pk.pack(1); // ["test.tag", [[123400xxx, {"a": 1}]]]
  pk.pack(k2); pk.pack(2); // ["test.tag", [[123400xxx, {"a": 1, "b": 2}]]]
        
  write(sock, buf.data(), buf.size());

}


int main() {
  int sock = connect_tcp("localhost", "24224");
  send_msg(sock);
}