[Positioning] OutputUDPSocket: finish cleaning

Use libowlps for socket creation.
Use Result::to_csv() and ResultList::to_csv().

owlps-positioning/src/outputudpsocket.cc

@@ -1,18 +1,15 @@
 #include "outputudpsocket.hh"
 #include "request.hh"
 #include "resultlist.hh"
+#include "posexcept.hh"
+
+#include <owlps.h>
 
 #include <sstream>
-#include <iostream>
-
-#include <netdb.h>
-#include <cstring>
+#include <cstdio> // For perror()
 
 using namespace std ;
 
-struct hostent *hostInfo ;
-struct sockaddr_in serverAddress ;
-
 
 
 /* *** Constructors *** */
@@ -22,13 +19,15 @@ OutputUDPSocket::OutputUDPSocket(const string &_remote_host,
                                  const uint_fast16_t _remote_port):
   remote_host(_remote_host), remote_port(_remote_port)
 {
-  init_socket() ;
+  if (! init_socket())
+    throw error_opening_output_file("UDP socket") ;
+
 }
 
 
 OutputUDPSocket::~OutputUDPSocket()
 {
-  kill_socket() ;
+  close_socket() ;
 }
 
 
@@ -36,56 +35,63 @@ OutputUDPSocket::~OutputUDPSocket()
 /* *** Operations *** */
 
 
-void OutputUDPSocket::write(const ResultList &results)
+/**
+ * @return true if the socket were successfully opened, false in case of
+ * error.
+ */
+bool OutputUDPSocket::init_socket()
 {
-  // Not implemented
+  sockfd = owl_create_udp_trx_socket(remote_host.c_str(), remote_port,
+                                     &server_info, &client_info) ;
+  return sockfd >= 0 ;
+}
+
+
+/**
+ * Normally, the socket is closed automatically by the destructor. Use
+ * this if you want to close the socket prematurely.
+ * #sockfd is set to -1, even in case of error.
+ * @return \em true if the socket were successfully closed or were not
+ * opened.
+ * @return \em false in case of error.
+ */
+bool OutputUDPSocket::close_socket()
+{
+  if (sockfd >= 0)
+    {
+      if (close(sockfd))
+        {
+          perror("Cannot close UDP socket") ;
+          return false ;
+        }
+
+      sockfd = -1 ;
+    }
+
+  return true ;
 }
 
 
 void OutputUDPSocket::write(const Result &result)
 {
-  string timestampXYZ;
-  ostringstream os;
-
-  Point3D position = result.get_position() ;
-
-  os
-      << position.get_x() << ';'
-      << position.get_y() << ';'
-      << position.get_z() ;
-  timestampXYZ = os.str() ;
-
-  cout << timestampXYZ << '\n' ;
-  send_data(timestampXYZ);
+  send_data(result.to_csv()) ;
 }
 
 
-void OutputUDPSocket::init_socket()
+void OutputUDPSocket::write(const ResultList &results)
 {
-  cout << "Initialisation socket..." << endl;
-  hostInfo = gethostbyname(remote_host.c_str());
-  socketDescriptor = socket(AF_INET, SOCK_DGRAM, 0);
-  serverAddress.sin_family = hostInfo->h_addrtype;
-  memcpy((char *) &serverAddress.sin_addr.s_addr,
-         hostInfo->h_addr_list[0], hostInfo->h_length);
-  serverAddress.sin_port = htons(remote_port);
+  send_data(results.to_csv()) ;
 }
 
 
-void OutputUDPSocket::send_data(string data)
+/**
+ * Sends the text buffer 'data'.
+ */
+void OutputUDPSocket::send_data(const string &data)
 {
-  if (sendto(socketDescriptor, data.c_str(), data.size(), 0,
-             (struct sockaddr *) &serverAddress,
-             sizeof(serverAddress)) < 0)
-    {
-      cerr << "Émission du message impossible\n";
-      close(socketDescriptor);
-    }
-}
-
-
-void OutputUDPSocket::kill_socket()
-{
-  cout << "Fermeture de la socket..." << endl;
-  close(socketDescriptor);
+  ssize_t nsent = sendto(sockfd, data.c_str(), data.size(), 0,
+                         (struct sockaddr *) &server_info,
+                         sizeof(server_info)) ;
+  if (nsent != static_cast<ssize_t>(data.size()))
+    perror("Error sending result data") ;
 }

owlps-positioning/src/outputudpsocket.hh

@@ -5,21 +5,28 @@
 
 #include <string>
 #include <stdint.h> // <cstdint> is not C++ 98 compliant
+#include <arpa/inet.h>
 
-/// Sends results to an UDP socket
+/// Sends results to a remote host by UDP
+/**
+ * The results are sent through an UDP socket as a CSV string value. The
+ * format used is the same as in OutputCSV.
+ */
 class OutputUDPSocket: public OutputMedium
 {
-private:
-  int socketDescriptor ;
+protected:
+  int sockfd ;
   std::string remote_host ;
   uint_fast16_t remote_port ;
 
+  struct sockaddr_in server_info ;
+  struct sockaddr_in client_info ;
+
   /** @name Operations */
   //@{
   /// Initialises the socket
-  void init_socket(void) ;
-  void kill_socket(void) ;
-  void send_data(std::string msg) ;
+  bool init_socket(void) ;
+  void send_data(const std::string &data) ;
   //@}
 
 public:
@@ -29,9 +36,10 @@ public:
 
   /** @name Operations */
   //@{
-  /// Initialises the socket
   void write(const Result &result) ;
   void write(const ResultList &results) ;
+  /// Closes the socket
+  bool close_socket(void) ;
   //@}
 } ;