Major refactor

src/tcp_socket.cpp

@@ -0,0 +1,133 @@
+#include <endian.h>
+#include <netinet/tcp.h>
+#include <unistd.h>
+#include <cstring>
+
+#include "ur_modern_driver/log.h"
+#include "ur_modern_driver/tcp_socket.h"
+
+TCPSocket::TCPSocket()
+  : socket_fd_(-1)
+  , state_(SocketState::Invalid)
+{ 
+}
+TCPSocket::~TCPSocket()
+{
+  close();
+}
+
+bool TCPSocket::setup(std::string &host, int port)
+{
+  if(state_ == SocketState::Connected)
+    return false;
+
+  LOG_INFO("Setting up connection: %s:%d", host.c_str(), port);
+
+  // gethostbyname() is deprecated so use getadderinfo() as described in:
+  // http://www.beej.us/guide/bgnet/output/html/multipage/syscalls.html#getaddrinfo
+
+  const char *host_name = host.empty() ? nullptr : host.c_str();
+  std::string service = std::to_string(port);
+  struct addrinfo hints, *result;
+  std::memset(&hints, 0, sizeof(hints));
+
+  hints.ai_family = AF_UNSPEC;
+  hints.ai_socktype = SOCK_STREAM;
+  hints.ai_flags = AI_PASSIVE;
+
+  if (getaddrinfo(host_name, service.c_str(), &hints, &result) != 0)
+  {
+    LOG_ERROR("Failed to get address for %s:%d", host.c_str(), port);
+    return false;
+  }
+
+  bool connected = false;
+  // loop through the list of addresses untill we find one that's connectable
+  for (struct addrinfo* p = result; p != nullptr; p = p->ai_next)
+  {
+    socket_fd_ = ::socket(p->ai_family, p->ai_socktype, p->ai_protocol);
+
+    if (socket_fd_ != -1 && open(socket_fd_, p->ai_addr, p->ai_addrlen)) 
+    {
+      connected = true;
+      break;
+    }
+  }
+
+  freeaddrinfo(result);
+  
+  if(!connected)
+  {
+    state_ = SocketState::Invalid;
+    LOG_ERROR("Connection setup failed for %s:%d", host.c_str(), port);
+  }
+  else
+  {
+    state_ = SocketState::Connected;
+    LOG_INFO("Connection established for %s:%d", host.c_str(), port);
+  }
+  return connected;
+}
+
+bool TCPSocket::setSocketFD(int socket_fd)
+{
+  if(state_ == SocketState::Connected)
+    return false;
+  socket_fd_ = socket_fd;
+  state_ = SocketState::Connected;
+  return true;
+}
+
+void TCPSocket::close()
+{
+  if(state_ != SocketState::Connected)
+    return;
+  state_ = SocketState::Closed;
+  ::shutdown(socket_fd_, SHUT_RDWR);
+  socket_fd_ = -1;
+}
+
+bool TCPSocket::read(uint8_t *buf, size_t buf_len, size_t &read)
+{
+  read = 0;
+
+  if(state_ != SocketState::Connected)
+    return false;
+    
+  ssize_t res = ::recv(socket_fd_, buf, buf_len, 0);
+
+  if(res == 0)
+  {
+    state_ = SocketState::Disconnected;
+    return false;
+  }
+  else if(res < 0)
+    return false;
+
+  read = static_cast<size_t>(res);
+  return true;
+}
+
+bool TCPSocket::write(const uint8_t *buf, size_t buf_len, size_t &written)
+{
+  written = 0;
+  
+  if(state_ != SocketState::Connected)
+    return false;
+
+  size_t remaining = buf_len;
+
+  // handle partial sends
+  while (written < buf_len)
+  {
+    ssize_t sent = ::send(socket_fd_, buf + written, remaining, 0);
+
+    if (sent <= 0)
+      return false;
+    
+    written += sent;
+    remaining -= sent;
+  }
+  
+  return true;
+}