Make conferences persistent across restarts and reconnects.

This is not new groupchats. This is just upgrade to old groupchats with
some advantages:
- Groupchats are now saved into tox_save.
- Clients can get groupchat unique id to save message log.
- Auto restore groupchats after restart even your friend uses
  non-upgraded version.

auto_tests/conference_test.c

@@ -15,7 +15,7 @@
 #include "../toxcore/util.h"
 #include "check_compat.h"
 
-#define NUM_GROUP_TOX 5
+#define NUM_GROUP_TOX 16
 #define GROUP_MESSAGE "Install Gentoo"
 
 static void handle_self_connection_status(

conference-stress-test

@@ -0,0 +1,15 @@
+#!/usr/bin/make -f
+
+RESULTS := $(foreach i,$(shell seq 0 10),$(shell printf "results/%02d.log" $i))
+
+.SILENT:
+run: $(RESULTS)
+
+results/%.log: auto_conference_test
+	echo "TEST $< > $@"
+	mkdir -p $(@D)
+	./auto_conference_test > $@ 2>&1
+
+.PHONY: auto_conference_test
+auto_conference_test:
+	$(MAKE) $@

toxav/groupav.c

@@ -458,7 +458,7 @@ static int groupchat_enable_av(const Logger *log, Group_Chats *g_c, uint32_t gro
 int add_av_groupchat(const Logger *log, Group_Chats *g_c, void (*audio_callback)(Messenger *, uint32_t, uint32_t,
                      const int16_t *, unsigned int, uint8_t, uint32_t, void *), void *userdata)
 {
-    int groupnumber = add_groupchat(g_c, GROUPCHAT_TYPE_AV);
+    int groupnumber = add_groupchat(g_c, GROUPCHAT_TYPE_AV, nullptr);
 
     if (groupnumber == -1) {
         return -1;
@@ -475,21 +475,21 @@ int add_av_groupchat(const Logger *log, Group_Chats *g_c, void (*audio_callback)
 /* Join a AV group (you need to have been invited first.)
  *
  * returns group number on success
- * returns -1 on failure.
+ * returns -1 .. -6 on failure (see join_groupchat)
  */
 int join_av_groupchat(const Logger *log, Group_Chats *g_c, uint32_t friendnumber, const uint8_t *data, uint16_t length,
                       void (*audio_callback)(Messenger *, uint32_t, uint32_t, const int16_t *, unsigned int, uint8_t, uint32_t, void *),
                       void *userdata)
 {
     int groupnumber = join_groupchat(g_c, friendnumber, GROUPCHAT_TYPE_AV, data, length);
 
-    if (groupnumber == -1) {
-        return -1;
+    if (groupnumber < 0) {
+        return groupnumber;
     }
 
     if (groupchat_enable_av(log, g_c, groupnumber, audio_callback, userdata) == -1) {
         del_groupchat(g_c, groupnumber);
-        return -1;
+        return -5; /* initialization failed */
     }
 
     return groupnumber;

toxav/toxav.api.h

@@ -622,7 +622,7 @@ int toxav_add_av_groupchat(Tox *tox, void (*audio_callback)(void *, uint32_t, ui
 /* Join a AV group (you need to have been invited first.)
  *
  * returns group number on success
- * returns -1 on failure.
+ * returns < 0 on failure.
  *
  * Audio data callback format (same as the one for toxav_add_av_groupchat()):
  *   audio_callback(Tox *tox, uint32_t groupnumber, uint32_t peernumber, const int16_t *pcm, unsigned int samples, uint8_t channels, uint32_t sample_rate, void *userdata)

toxav/toxav.h

@@ -751,7 +751,7 @@ int toxav_add_av_groupchat(Tox *tox, void (*audio_callback)(void *, uint32_t, ui
 /* Join a AV group (you need to have been invited first.)
  *
  * returns group number on success
- * returns -1 on failure.
+ * returns < 0 on failure.
  *
  * Audio data callback format (same as the one for toxav_add_av_groupchat()):
  *   audio_callback(Tox *tox, uint32_t groupnumber, uint32_t peernumber, const int16_t *pcm, unsigned int samples, uint8_t channels, uint32_t sample_rate, void *userdata)

toxav/toxav_old.c

@@ -47,7 +47,7 @@ int toxav_add_av_groupchat(Tox *tox, void (*audio_callback)(void *, uint32_t, ui
 /* Join a AV group (you need to have been invited first.)
  *
  * returns group number on success
- * returns -1 on failure.
+ * returns < 0 on failure.
  *
  * Audio data callback format (same as the one for toxav_add_av_groupchat()):
  *   audio_callback(Tox *tox, int groupnumber, int peernumber, const int16_t *pcm, unsigned int samples, uint8_t channels, unsigned int sample_rate, void *userdata)

toxcore/Messenger.c

@@ -2749,6 +2749,7 @@ void do_messenger(Messenger *m, void *userdata)
 #define MESSENGER_STATE_TYPE_STATUS        6
 #define MESSENGER_STATE_TYPE_TCP_RELAY     10
 #define MESSENGER_STATE_TYPE_PATH_NODE     11
+#define MESSENGER_STATE_TYPE_CONFERENCES   100
 #define MESSENGER_STATE_TYPE_END           255
 
 #define SAVED_FRIEND_REQUEST_SIZE 1024
@@ -2966,6 +2967,32 @@ static int friends_list_load(Messenger *m, const uint8_t *data, uint32_t length)
     return num;
 }
 
+// Empty definitions of the conference load/save functions. These are set if the
+// groups module is loaded. In tox_new, the group module is initialised, so
+// public API users will never see calls to these functions.
+static uint32_t saved_conferences_size_default(const Messenger *m)
+{
+    return 0;
+}
+static void conferences_save_default(const Messenger *m, uint8_t *data)
+{
+    return;
+}
+static int conferences_load_default(Messenger *m, const uint8_t *data, uint32_t length)
+{
+    return 0;
+}
+
+// HACK HACK HACK to make conferences load/save work.
+// TODO(robinlinden): Refactor this.
+//!TOKSTYLE-
+// Invalid in TokTok style, because we don't allow global mutable state.
+saved_conferences_size_cb *saved_conferences_size_ptr = saved_conferences_size_default;
+conferences_save_cb *conferences_save_ptr = conferences_save_default;
+conferences_load_cb *conferences_load_ptr = conferences_load_default;
+//!TOKSTYLE+
+
+
 /*  return size of the messenger data (for saving) */
 uint32_t messenger_size(const Messenger *m)
 {
@@ -2979,6 +3006,7 @@ uint32_t messenger_size(const Messenger *m)
              + sizesubhead + 1                                 // status
              + sizesubhead + NUM_SAVED_TCP_RELAYS * packed_node_size(net_family_tcp_ipv6) // TCP relays
              + sizesubhead + NUM_SAVED_PATH_NODES * packed_node_size(net_family_tcp_ipv6) // saved path nodes
+             + sizesubhead + saved_conferences_size_ptr(m)     // old group chats
              + sizesubhead;
 }
 
@@ -3070,6 +3098,12 @@ void messenger_save(const Messenger *m, uint8_t *data)
         data += len;
     }
 
+    len = saved_conferences_size_ptr(m);
+    type = MESSENGER_STATE_TYPE_CONFERENCES;
+    data = messenger_save_subheader(data, len, type);
+    conferences_save_ptr(m, data);
+    data += len;
+
     messenger_save_subheader(data, 0, MESSENGER_STATE_TYPE_END);
 }
 
@@ -3148,6 +3182,20 @@ static State_Load_Status messenger_load_state_callback(void *outer, const uint8_
             break;
         }
 
+        case MESSENGER_STATE_TYPE_CONFERENCES: {
+            int err = conferences_load_ptr(m, data, length);
+
+            /* No need to do something special if err < 0
+             * err < 0 just means that conferences data was damaged
+             * and skipped
+             */
+            if (err < 0) {
+                LOGGER_ERROR(m->log, "conference savedata was corrupted");
+            }
+
+            break;
+        }
+
         case MESSENGER_STATE_TYPE_END: {
             if (length != 0) {
                 return STATE_LOAD_STATUS_ERROR;
@@ -3157,7 +3205,7 @@ static State_Load_Status messenger_load_state_callback(void *outer, const uint8_
         }
 
         default:
-            LOGGER_ERROR(m->log, "Load state: contains unrecognized part (len %u, type %u)\n",
+            LOGGER_ERROR(m->log, "Load state: contains unrecognized part (len %u, type %u)",
                          length, type);
             break;
     }

toxcore/Messenger.h

@@ -781,4 +781,14 @@ uint32_t count_friendlist(const Messenger *m);
  * of out_list will be truncated to list_size. */
 uint32_t copy_friendlist(const Messenger *m, uint32_t *out_list, uint32_t list_size);
 
+typedef uint32_t saved_conferences_size_cb(const Messenger *m);
+typedef void conferences_save_cb(const Messenger *m, uint8_t *data);
+typedef int conferences_load_cb(Messenger *m, const uint8_t *data, uint32_t length);
+
+// HACK HACK HACK to make conferences load/save work.
+// TODO(robinlinden): Refactor this.
+extern saved_conferences_size_cb *saved_conferences_size_ptr;
+extern conferences_save_cb *conferences_save_ptr;
+extern conferences_load_cb *conferences_load_ptr;
+
 #endif