allow resuming of broken file transfers (needs testing)

src/chat.c

@@ -176,6 +176,9 @@ static void chat_onMessage(ToxWindow *self, Tox *m, int32_t num, const char *msg
     
 }
 
+static void chat_resume_file_transfers(Tox *m, int fnum);
+static void chat_stop_file_senders(int fnum);
+
 static void chat_onConnectionChange(ToxWindow *self, Tox *m, int32_t num, uint8_t status)
 {
     if (self->num != num)
@@ -187,13 +190,15 @@ static void chat_onConnectionChange(ToxWindow *self, Tox *m, int32_t num, uint8_
         statusbar->is_online = true;
         Friends.list[num].is_typing = user_settings_->show_typing_other == SHOW_TYPING_ON 
                                  ? tox_get_is_typing(m, num) : 0;
-                                 
+        chat_resume_file_transfers(m, num);             
     } else { /* Friend goes offline */
         statusbar->is_online = false;
         Friends.list[num].is_typing = 0;
 
         if (self->chatwin->self_is_typing)
             set_self_typingstatus(self, m, 0);
+
+        chat_stop_file_senders(num);
     }
 }
 
@@ -350,6 +355,36 @@ static void chat_onFileSendRequest(ToxWindow *self, Tox *m, int32_t num, uint8_t
                     "Incoming file: %s", filename );
 }
 
+/* Stops active file senders for this friend. Call when a friend goes offline */
+static void chat_stop_file_senders(int fnum)
+{
+    int i;
+
+    for (i = 0; i < MAX_FILES; ++i) {
+        if (file_senders[i].active && file_senders[i].friendnum == fnum)
+            file_senders[i].noconnection = true;
+    }
+}
+
+/* Tries to resume broken file transfers. Call when a friend comes online */
+static void chat_resume_file_transfers(Tox *m, int fnum)
+{
+    if (Friends.list[fnum].active_file_receivers == 0)
+        return;
+
+    int i;
+
+    for (i = 0; i < MAX_FILES; ++i) {
+        if (Friends.list[fnum].file_receiver[i].active && !Friends.list[fnum].file_receiver[i].paused) {
+            uint8_t bytes_recv[sizeof(uint64_t)];
+            memcpy(bytes_recv, &Friends.list[fnum].file_receiver[i].bytes_recv, sizeof(uint64_t));
+            net_to_host(bytes_recv, sizeof(uint64_t));
+            int filenum = Friends.list[fnum].file_receiver[i].filenum;
+            tox_file_send_control(m, fnum, 1, filenum, TOX_FILECONTROL_RESUME_BROKEN, bytes_recv, sizeof(uint64_t));
+        }
+    }
+}
+
 /* set CTRL to -1 if we don't want to send a control signal.
    set msg to NULL if we don't want to display a message */
 void chat_close_file_receiver(Tox *m, int filenum, int friendnum, int CTRL)
@@ -363,6 +398,7 @@ void chat_close_file_receiver(Tox *m, int filenum, int friendnum, int CTRL)
         fclose(file);
 
     memset(&Friends.list[friendnum].file_receiver[filenum], 0, sizeof(struct FileReceiver));
+    --Friends.list[friendnum].active_file_receivers;
 }
 
 static void close_all_file_receivers(Tox *m, int friendnum)
@@ -453,6 +489,26 @@ static void chat_onFileControl(ToxWindow *self, Tox *m, int32_t num, uint8_t rec
                             self->name, "%s", msg);
 
             break;
+
+        case TOX_FILECONTROL_RESUME_BROKEN:
+            if (receive_send == 0)
+                break;
+
+            FILE *fp = file_senders[i].file;
+
+            if (fp == NULL)
+                break;
+
+            uint8_t tmp[sizeof(uint64_t)];
+            memcpy(tmp, &data, sizeof(uint64_t));
+            net_to_host(tmp, sizeof(uint64_t));
+            uint64_t datapos;
+            memcpy(&datapos, tmp, sizeof(uint64_t));
+
+            fseek(fp, datapos, SEEK_SET);
+            tox_file_send_control(m, num, 0, filenum, TOX_FILECONTROL_ACCEPT, 0, 0);
+            file_senders[i].noconnection = false;
+            break;
     }
 
     if (msg[0])
@@ -475,6 +531,7 @@ static void chat_onFileData(ToxWindow *self, Tox *m, int32_t num, uint8_t filenu
     }
 
     Friends.list[num].file_receiver[filenum].bps += length;
+    Friends.list[num].file_receiver[filenum].bytes_recv += length;
     double remain = (double) tox_file_data_remaining(m, num, filenum, 1);
     uint64_t curtime = get_unix_time();
 

src/chat_commands.c

@@ -177,13 +177,15 @@ void cmd_savefile(WINDOW *window, ToxWindow *self, Tox *m, int argc, char (*argv
         if ((Friends.list[self->num].file_receiver[filenum].file = fopen(filename, "a")) == NULL) {
             line_info_add(self, NULL, NULL, NULL, SYS_MSG, 0, RED, "* Error writing to file.");
             tox_file_send_control(m, self->num, 1, filenum, TOX_FILECONTROL_KILL, 0, 0);
+        } else {
+            Friends.list[self->num].file_receiver[filenum].active = true;
+            ++Friends.list[self->num].active_file_receivers;
         }
     } else {
         line_info_add(self, NULL, NULL, NULL, SYS_MSG, 0, 0, "File transfer failed.");
     }
 
     Friends.list[self->num].file_receiver[filenum].pending = false;
-    Friends.list[self->num].file_receiver[filenum].active = true;
 }
 
 void cmd_sendfile(WINDOW *window, ToxWindow *self, Tox *m, int argc, char (*argv)[MAX_STR_SIZE])

src/dns.c

@@ -44,13 +44,14 @@
 
 #define DNS3_KEY_SIZE 32
 #define MAX_DNS_REQST_SIZE 255
-#define NUM_DNS3_BACKUP_SERVERS 2    /* must correspond to number of items in dns3_servers array */
 #define TOX_DNS3_TXT_PREFIX "v=tox3;id="
 
 extern struct _Winthread Winthread;
 extern struct _dns3_servers dns3_servers;
 extern struct arg_opts arg_opts;
 
+#define NUM_DNS3_BACKUP_SERVERS 2
+
 /* Hardcoded backup in case domain list is not loaded */
 static struct dns3_server_backup {
     const char *name;

src/file_senders.c

@@ -217,7 +217,9 @@ void do_file_senders(Tox *m)
             continue;
         }
 
-        send_file_data(self, m, i, friendnum, filenum, filename);
+        if (file_senders[i].noconnection == false)
+            send_file_data(self, m, i, friendnum, filenum, filename);
+
         file_senders[i].queue_pos = num_active_file_senders - 1;
     }
 }

src/file_senders.h

@@ -40,6 +40,7 @@ typedef struct {
     ToxWindow *toxwin;
     int32_t friendnum;
     bool active;
+    bool noconnection;
     bool finished;
     int filenum;
     char nextpiece[FILE_PIECE_SIZE];

src/friendlist.h

@@ -35,9 +35,11 @@ struct FileReceiver {
     FILE *file;
     bool pending;
     bool active;
+    bool paused;
     uint64_t size;
+    uint64_t bytes_recv;
     double bps;
-    uint64_t last_progress;
+    uint64_t last_progress;   /* unix-time when we last updated progress */
     uint32_t line_id;
 };
 
@@ -64,6 +66,7 @@ typedef struct {
     uint8_t status;
     struct LastOnline last_online;
     struct FileReceiver file_receiver[MAX_FILES];
+    uint8_t active_file_receivers;
 } ToxicFriend;
 
 typedef struct {