adding comments + cleaner for sender

src/sender.c

@@ -132,7 +132,7 @@ int main(int argc, char **argv) {
             return EXIT_FAILURE;
         }
 
-        // Setting a timer only when waiting for the last ACK (so the sender buffer is 30)
+        // Setting a timer only when waiting for the very last ACK
         gettimeofday(&curr_time, NULL);
         if (state->last_pkt_sent == CLOSING_PKT && ((curr_time.tv_sec - closing_pkt_sent_time.tv_sec) > SENDER_INACTIVE_TIMEOUT))
         {
@@ -179,8 +179,8 @@ int main(int argc, char **argv) {
             rvalue = checking_timer(state, socket_fd);
             if (rvalue == -1)
             {
-                // If an error occured when trying to send back the closing pkt,
-                // we guess that the receiver has simply disconnected and the ACK of the closing pkt was lost.
+                // If an error occured when trying to send back the CLOSING_PKT,
+                // we guess that the receiver has simply disconnected and the ACK of the CLOSING_PKT was lost.
                 if (state->last_pkt_sent == CLOSING_PKT)
                 {
                     DEBUG("The sender can't send anything to the receiver anymore (which has probably disconnected) so it'll disconnect !");

src/sender_utils.c

@@ -38,7 +38,7 @@ void state_del(sender_state_t *state)
     free(state);
 }
 
-int can_send(sender_state_t *state)
+bool can_send(sender_state_t *state)
 {
     if (state->last_pkt_sent == RANDOM_DATA_PKT)
     {
@@ -48,7 +48,7 @@ int can_send(sender_state_t *state)
     {
         // I want to be sure all the data pkt has been received before letting know the receiver
         // it was the end of the file (so that I can set a timer for timeout)
-        return state->s_window_size == WINDOW_SIZE;
+        return state->s_window_size == MAX_WINDOW_SIZE;
     }
     else
     {
@@ -127,7 +127,7 @@ int handle_returning_ack_nack(sender_state_t *state, int socket_fd)
         uint8_t place_last_ack  = state->map_seqnum_to_buffer_place[seqnum_ack];
         uint8_t place_last_nack = state->map_seqnum_to_buffer_place[seqnum_nack];
         
-        // Nothing new need to be acked
+        // Nothing need to be acked
         if (place_last_ack == OUT_OFF_WINDOW)
         {
             // Checking if it's in my window:
@@ -178,7 +178,6 @@ int handle_returning_ack_nack(sender_state_t *state, int socket_fd)
 int checking_timer(sender_state_t *state, int socket_fd)
 {
     struct timeval time;
-
     // Checking if the slot contains a sended packet
     if (state->buffer[state->tail] != NULL)
     {

src/sender_utils.h

@@ -17,13 +17,13 @@
 #include "packet_interface.h"
 
 
-#define SEQNUM_RANGE 256
-#define TIMER_LIMIT 2  // It's in seconds, in this network, the latency to send is = [0, 2s]
-#define SENDER_INACTIVE_TIMEOUT 30 // Only waits 30sec for the last ACK
-#define WINDOW_SIZE 31
-#define OUT_OFF_WINDOW 255
+#define SEQNUM_RANGE            256
+#define TIMER_LIMIT             2   // It's in seconds, in this network, the latency to send is = [0, 2s]
+#define SENDER_INACTIVE_TIMEOUT 30  // Only waits 30sec for the ACK of the CLOSING_PKT (the very last sended pkt)
+#define WINDOW_SIZE             31
+#define OUT_OFF_WINDOW          255
 
-// It is used to identify what kind of pkt what send lately
+// It is used to identify what kind of pkt was sent lately
 #define RANDOM_DATA_PKT 0
 #define LAST_DATA_PKT   1
 #define CLOSING_PKT     2
@@ -37,8 +37,8 @@ typedef struct state {
     uint8_t s_window_size; // sender (our) buffer space
     time_t  timers[WINDOW_SIZE];  // Time in seconds (corresponds to the timers of the sended pkt)
     pkt_t  *buffer[WINDOW_SIZE];  // When the buffer fields are not used, they MUST be se to NULL
-    uint8_t head;  // place last element insert +1 in the buffer (free place) | Head and tail are used
-    uint8_t tail;  // place oldest element insert in the buffer               | used to know the start of the sended window
+    uint8_t head;  // place last element insert +1 in the buffer (free place)  | Head and tail are used to know
+    uint8_t tail;  // place oldest element insert in the buffer                | the start and end of the sender window (of the sended pkt)
     uint8_t next_seqnum;
     uint8_t map_seqnum_to_buffer_place[SEQNUM_RANGE]; // Default value is: OUT_OFF_WINDOW
     uint8_t last_pkt_sent;  // Can either be: RANDOM_DATA_PKT, LAST_DATA_PKT or CLOSING_PKT
@@ -60,12 +60,16 @@ sender_state_t *state_new();
 void state_del(sender_state_t *state);
 
 /**
- * @brief Checking if both the sender and receiver buffer has some room left
+ * @brief Checking if the sender is allowed to send a NEW pkt
  * 
  * @param state : The variable representing the sender (state).
- * @return int  : 1 if there are enough space in the buffer, 0 otherwise.
+ * @return bool : 
+ *          - true : if there are enough room in the buffers and some pkt still need to be sent
+ *          - false: if there are no room in the buffer 
+ *                   or if we're waiting for the last ACK of the DATATYPE
+ *                   or if all pkt have been sent 
  */
-int can_send(sender_state_t *state);
+bool can_send(sender_state_t *state);
 
 /**
  * @brief Cautious this function is used for sending and sending back pkt !
@@ -79,32 +83,32 @@ int can_send(sender_state_t *state);
 int send_pkt(sender_state_t *state, pkt_t *pkt, uint8_t position, int socket_fd);
 
 /**
- * @brief 
+ * @brief The function handle ACK and NACK pkt.
  * 
- * @param state 
- * @param socket_fd 
- * @return int 
+ * @param state     : The variable representing the sender (state).
+ * @param socket_fd : The socket on which pkt are sent.
+ * @return int      : 0 if no error, -1 otherwise
  */
 int handle_returning_ack_nack(sender_state_t *state, int socket_fd);
 
 /**
- * @brief 
+ * @brief The function checks if the oldest not acked pkt has exceeded the timer (TIMER_LIMIT).
+ *        If it has exceeded the timer then it is sent back.
  * 
- * @param state 
- * @param socket_fd 
- * @return int 
+ * @param state     : The variable representing the sender (state).
+ * @param socket_fd : The socket on which pkt are sent.
+ * @return int      : 0 if no error, -1 otherwise
  */
 int checking_timer(sender_state_t *state, int socket_fd);
 
 /**
- * @brief When this function is called, the sender MUST be allowed to send a data pkt
+ * @brief When this function is called, the sender MUST be allowed to send a data pkt.
+ *        It sends the next pkt and update the variable 'last_pkt_sent' of state.
  * 
- * @param state 
- * @param sending_fd 
- * @param socket_fd 
- * @return int : 1 if it has sent the empty datatype pkt else 0
- *               -1 if an error occured
- *               -2 Both sender and receiver buffer are full
+ * @param state      : The variable representing the sender (state).
+ * @param sending_fd : The file descriptor of the file to be send
+ * @param socket_fd  : The socket on which pkt are sent.
+ * @return int       : 0 if no error, -1 otherwise
  */
 int read_and_send(sender_state_t *state, int sending_fd, int socket_fd);
 

tests/simple_test.sh

@@ -33,9 +33,9 @@ cleanup()
 }
 trap cleanup SIGINT  # Kill les process en arrière plan en cas de ^-C
 
-# On démarre le transfert
+# We start the transfer
 if ! valgrind --leak-check=full --log-file=./unwanted_logs/valgrind_${BSNM_PRE}_sender.log ./sender -f ${FILENAME} ::1 65197 2> ./unwanted_logs/${BSNM_PRE}_sender.log ; then
-  echo "Crash du sender!"
+  echo "The sender crashed!"
   cat ./unwanted_logs/${BSNM_PRE}_sender.log
   err=1  # On enregistre l'erreur
 fi
@@ -46,21 +46,21 @@ if kill -0 $receiver_pid &> /dev/null ; then
   echo "Le receiver ne s'est pas arreté à la fin du transfert!"
   kill -9 $receiver_pid
   err=1
-else  # On teste la valeur de retour du receiver
+else  # We check the return value of the receiver
   if ! wait $receiver_pid ; then
-    echo "Crash du receiver!"
+    echo "The receiver crashed!"
     cat ./unwanted_logs/${BSNM_PRE}_receiver.log
     err=1
   fi
 fi
 
-# On vérifie que le transfert s'est bien déroulé
+# We check that the transfer ran through properly
 if [[ "$(md5sum ${FILENAME} | awk '{print $1}')" != "$(md5sum ./unwanted_logs/${BSNM_PRE}_received_file.${BSNM_EXT} | awk '{print $1}')" ]]; then
-  echo "Le transfert a corrompu le fichier!"
+  echo "The transfer has corrupted the file!"
   echo "Diff binaire des deux fichiers: (attendu vs produit)"
   diff -C 9 <(od -Ax -t x1z ${FILENAME}) <(od -Ax -t x1z ./unwanted_logs/${BSNM_PRE}_received_file.${BSNM_EXT})
   exit 1
 else
-  echo -e "${GREEN}Le transfert est réussi!${NC}"
-  exit ${err:-0}  # En cas d'erreurs avant, on renvoie le code d'erreur
+  echo -e "${GREEN}The transfer has succeeded!${NC}"
+  exit ${err:-0}  # In case of error, we send back the error code.
 fi
\ No newline at end of file