Fix file transfers breaking when friends go offline

src/chat.c

@@ -188,8 +188,8 @@ static void chat_onMessage(ToxWindow *self, Tox *m, uint32_t num, TOX_MESSAGE_TY
         return recv_action_helper(self, m, num, msg, len, nick, timefrmt);
 }
 
-static void chat_resume_file_transfers(Tox *m, uint32_t fnum);
+static void chat_pause_file_transfers(Tox *m, uint32_t friendnum);
-static void chat_stop_file_senders(Tox *m, uint32_t friendnum);
+static void chat_resume_file_senders(ToxWindow *self, Tox *m, uint32_t fnum);
 
 static void chat_onConnectionChange(ToxWindow *self, Tox *m, uint32_t num, TOX_CONNECTION connection_status)
 {
@@ -209,7 +209,7 @@ static void chat_onConnectionChange(ToxWindow *self, Tox *m, uint32_t num, TOX_C
     if (connection_status != TOX_CONNECTION_NONE && statusbar->connection == TOX_CONNECTION_NONE) {
         Friends.list[num].is_typing = user_settings->show_typing_other == SHOW_TYPING_ON
                                       ? tox_friend_get_typing(m, num, NULL) : false;
-        chat_resume_file_transfers(m, num);
+        chat_resume_file_senders(self, m, num);
 
         msg = "has come online";
         line_info_add(self, timefrmt, nick, NULL, CONNECTION, 0, GREEN, msg);
@@ -220,7 +220,7 @@ static void chat_onConnectionChange(ToxWindow *self, Tox *m, uint32_t num, TOX_C
         if (self->chatwin->self_is_typing)
             set_self_typingstatus(self, m, 0);
 
-        chat_stop_file_senders(m, num);
+        chat_pause_file_transfers(m, num);
 
         msg = "has gone offline";
         line_info_add(self, timefrmt, nick, NULL, DISCONNECTION, 0, RED, msg);
@@ -277,17 +277,44 @@ static void chat_onReadReceipt(ToxWindow *self, Tox *m, uint32_t num, uint32_t r
     cqueue_remove(self, m, receipt);
 }
 
-/* Stops active file senders for this friend. Call when a friend goes offline */
+/* Stops active file transfers for this friend. Called when a friend goes offline */
-static void chat_stop_file_senders(Tox *m, uint32_t friendnum)
+static void chat_pause_file_transfers(Tox *m, uint32_t friendnum)
 {
-    // TODO: core purges file transfers when a friend goes offline. Ideally we want to repair/resume
+    ToxicFriend *friend = &Friends.list[friendnum];
-    kill_all_file_transfers_friend(m, friendnum);
+
+    size_t i;
+
+    for (i = 0; i < MAX_FILES; ++i) {
+        if (friend->file_sender[i].state >= FILE_TRANSFER_STARTED)
+            friend->file_sender[i].state = FILE_TRANSFER_PAUSED;
+
+        if (friend->file_receiver[i].state >= FILE_TRANSFER_STARTED)
+            friend->file_receiver[i].state = FILE_TRANSFER_PAUSED;
+    }
 }
 
-/* Tries to resume broken file transfers. Call when a friend comes online */
+/* Tries to resume broken file senders. Called when a friend comes online */
-static void chat_resume_file_transfers(Tox *m, uint32_t fnum)
+static void chat_resume_file_senders(ToxWindow *self, Tox *m, uint32_t friendnum)
 {
-    // TODO
+    size_t i;
+
+    for (i = 0; i < MAX_FILES; ++i) {
+        struct FileTransfer *ft = &Friends.list[friendnum].file_sender[i];
+
+        if (ft->state != FILE_TRANSFER_PAUSED)
+            continue;
+
+        TOX_ERR_FILE_SEND err;
+        ft->filenum = tox_file_send(m, friendnum, TOX_FILE_KIND_DATA, ft->file_size, ft->file_id,
+                                    (uint8_t *) ft->file_name, strlen(ft->file_name), &err);
+
+        if (err != TOX_ERR_FILE_SEND_OK) {
+            char msg[MAX_STR_SIZE];
+            snprintf(msg, sizeof(msg), "File transfer for '%s' failed.", ft->file_name);
+            close_file_transfer(self, m, ft, -1, msg, notif_error);
+            continue;
+        }
+    }
 }
 
 static void chat_onFileChunkRequest(ToxWindow *self, Tox *m, uint32_t friendnum, uint32_t filenum, uint64_t position,
@@ -428,12 +455,63 @@ static void chat_onFileControl(ToxWindow *self, Tox *m, uint32_t friendnum, uint
     }
 }
 
+/* Attempts to resume a broken inbound file transfer.
+ *
+ * Returns true if resume is successful.
+ */
+static bool chat_resume_broken_ft(ToxWindow *self, Tox *m, uint32_t friendnum, uint32_t filenum)
+{
+    char msg[MAX_STR_SIZE];
+    uint8_t file_id[TOX_FILE_ID_LENGTH];
+
+    if (!tox_file_get_file_id(m, friendnum, filenum, file_id, NULL))
+        return false;
+
+    bool resuming = false;
+    struct FileTransfer *ft = NULL;
+    size_t i;
+
+    for (i = 0; i < MAX_FILES; ++i) {
+        ft = &Friends.list[friendnum].file_receiver[i];
+
+        if (ft->state == FILE_TRANSFER_INACTIVE)
+            continue;
+
+        if (memcmp(ft->file_id, file_id, TOX_FILE_ID_LENGTH) == 0) {
+            ft->filenum = filenum;
+            resuming = true;
+            break;
+        }
+    }
+
+    if (!resuming || !ft)
+        return false;
+
+    if (!tox_file_seek(m, ft->friendnum, ft->filenum, ft->position, NULL))
+        goto on_error;
+
+    if (!tox_file_control(m, friendnum, filenum, TOX_FILE_CONTROL_RESUME, NULL))
+        goto on_error;
+
+    ft->state = FILE_TRANSFER_STARTED;
+    return true;
+
+on_error:
+    snprintf(msg, sizeof(msg), "File transfer for '%s' failed.", ft->file_name);
+    close_file_transfer(self, m, ft, -1, msg, notif_error);
+    return false;
+}
+
 static void chat_onFileRecv(ToxWindow *self, Tox *m, uint32_t friendnum, uint32_t filenum, uint64_t file_size,
                             const char *filename, size_t name_length)
 {
     if (self->num != friendnum)
         return;
 
+    /* first check if we need to resume a broken transfer */
+    if (chat_resume_broken_ft(self, m, friendnum, filenum))
+        return;
+
     struct FileTransfer *ft = get_new_file_receiver(friendnum);
 
     if (!ft) {
@@ -500,6 +578,7 @@ static void chat_onFileRecv(ToxWindow *self, Tox *m, uint32_t friendnum, uint32_
     ft->file_type = TOX_FILE_KIND_DATA;
     snprintf(ft->file_path, sizeof(ft->file_path), "%s", file_path);
     snprintf(ft->file_name, sizeof(ft->file_name), "%s", filename);
+    tox_file_get_file_id(m, friendnum, filenum, ft->file_id, NULL);
 
     if (self->active_box != -1)
         box_notify2(self, transfer_pending, NT_WNDALERT_0 | NT_NOFOCUS, self->active_box,

src/chat_commands.c

@@ -278,6 +278,7 @@ void cmd_sendfile(WINDOW *window, ToxWindow *self, Tox *m, int argc, char (*argv
     ft->friendnum = self->num;
     ft->direction = FILE_TRANSFER_SEND;
     ft->file_type = TOX_FILE_KIND_DATA;
+    tox_file_get_file_id(m, self->num, filenum, ft->file_id, NULL);
 
     char sizestr[32];
     bytes_convert_str(sizestr, sizeof(sizestr), filesize);

src/file_transfers.c

@@ -209,8 +209,6 @@ void close_file_transfer(ToxWindow *self, Tox *m, struct FileTransfer *ft, int C
     if (ft->file)
         fclose(ft->file);
 
-    memset(ft, 0, sizeof(struct FileTransfer));
-
     if (CTRL >= 0)
         tox_file_control(m, ft->friendnum, ft->filenum, (TOX_FILE_CONTROL) CTRL, NULL);
 
@@ -222,6 +220,8 @@ void close_file_transfer(ToxWindow *self, Tox *m, struct FileTransfer *ft, int C
 
         line_info_add(self, NULL, NULL, NULL, SYS_MSG, 0, 0, "%s", message);
     }
+
+    memset(ft, 0, sizeof(struct FileTransfer));
 }
 
 /* Kills all active file transfers for friendnum */

src/file_transfers.h

@@ -30,8 +30,8 @@
 #include "notify.h"
 
 #define KiB 1024
-#define MiB 1048576       /* 1024 ^ 2 */
+#define MiB 1048576       /* 1024^2 */
-#define GiB 1073741824    /* 1024 ^ 3 */
+#define GiB 1073741824    /* 1024^3 */
 
 #define MAX_FILES 32
 #define TIMEOUT_FILESENDER 120
@@ -40,7 +40,7 @@ typedef enum FILE_TRANSFER_STATE {
     FILE_TRANSFER_INACTIVE,
     FILE_TRANSFER_PENDING,
     FILE_TRANSFER_STARTED,
-    FILE_TRANSFER_PAUSED
+    FILE_TRANSFER_PAUSED,
 } FILE_TRANSFER_STATE;
 
 typedef enum FILE_TRANSFER_DIRECTION {
@@ -63,6 +63,7 @@ struct FileTransfer {
     uint64_t position;
     uint64_t last_progress;
     uint32_t line_id;
+    uint8_t  file_id[TOX_FILE_ID_LENGTH];
 };
 
 /* creates initial progress line that will be updated during file transfer.