add configurable limit on number of stored frozen peers

6 files changed, 178 insertions, 7 deletions

diff --git a/auto_tests/conference_test.c b/auto_tests/conference_test.c
index 5f08b823..ec88c82a 100644
--- a/auto_tests/conference_test.c
+++ b/auto_tests/conference_test.c
@@ -10,6 +10,8 @@
 #include <time.h>
 #include <stdint.h>
 
+#include "../toxcore/util.h"
+
 #include "check_compat.h"
 
 #define NUM_GROUP_TOX 16
@@ -199,6 +201,18 @@ static void run_conference_tests(Tox **toxes, State *state)
      * fails due to disconnections too short to trigger freezing */
     const bool check_name_change_propagation = false;
 
+    /* each peer should freeze at least its two friends, but freezing more
+     * should not be necessary */
+    const uint32_t max_frozen = max_u32(2, NUM_DISCONNECT / 2);
+    printf("restricting number of frozen peers to %u\n", max_frozen);
+
+    for (uint16_t i = 0; i < NUM_GROUP_TOX; ++i) {
+        Tox_Err_Conference_Set_Max_Offline err;
+        tox_conference_set_max_offline(toxes[i], 0, max_frozen, &err);
+        ck_assert_msg(err == TOX_ERR_CONFERENCE_SET_MAX_OFFLINE_OK,
+                      "tox #%u failed to set max offline: err = %d", state[i].index, err);
+    }
+
     printf("letting random toxes timeout\n");
     bool disconnected[NUM_GROUP_TOX] = {0};
     bool restarting[NUM_GROUP_TOX] = {0};
@@ -243,6 +257,7 @@ static void run_conference_tests(Tox **toxes, State *state)
             free(save[i]);
 
             set_mono_time_callback(toxes[i], &state[i]);
+            tox_conference_set_max_offline(toxes[i], 0, max_frozen, nullptr);
         }
     }
 
@@ -256,6 +271,13 @@ static void run_conference_tests(Tox **toxes, State *state)
         }
     }
 
+    for (uint16_t i = 0; i < NUM_GROUP_TOX; ++i) {
+        const uint32_t num_frozen = tox_conference_offline_peer_count(toxes[i], 0, nullptr);
+        ck_assert_msg(num_frozen <= max_frozen,
+                      "tox #%u has too many offline peers: %u\n",
+                      state[i].index, num_frozen);
+    }
+
     printf("reconnecting toxes\n");
 
     do {
diff --git a/toxcore/group.c b/toxcore/group.c
index 20ee5459..f6f8c704 100644
--- a/toxcore/group.c
+++ b/toxcore/group.c
@@ -118,6 +118,8 @@ static bool realloc_conferences(Group_Chats *g_c, uint16_t num)
 static void setup_conference(Group_c *g)
 {
     memset(g, 0, sizeof(Group_c));
+
+    g->maxfrozen = MAX_FROZEN_DEFAULT;
 }
 
 /* Create a new empty groupchat connection.
@@ -644,8 +646,8 @@ static int addpeer(Group_Chats *g_c, uint32_t groupnumber, const uint8_t *real_p
     id_copy(g->group[g->numpeers].temp_pk, temp_pk);
     g->group[g->numpeers].temp_pk_updated = true;
     g->group[g->numpeers].peer_number = peer_number;
-
     g->group[g->numpeers].last_active = mono_time_get(g_c->mono_time);
+    g->group[g->numpeers].is_friend = (getfriend_id(g_c->m, real_pk) != -1);
     ++g->numpeers;
 
     add_to_closest(g_c, groupnumber, real_pk, temp_pk);
@@ -752,6 +754,56 @@ static int delpeer(Group_Chats *g_c, uint32_t groupnumber, int peer_index, void
     return 0;
 }
 
+static int cmp_u64(uint64_t a, uint64_t b)
+{
+    return (a > b) - (a < b);
+}
+
+/* Order peers with friends first and with more recently active earlier */
+static int cmp_frozen(const void *a, const void *b)
+{
+    const Group_Peer *pa = (const Group_Peer *) a;
+    const Group_Peer *pb = (const Group_Peer *) b;
+
+    if (pa->is_friend ^ pb->is_friend) {
+        return pa->is_friend ? -1 : 1;
+    }
+
+    return cmp_u64(pb->last_active, pa->last_active);
+}
+
+/* Delete frozen peers as necessary to ensure at most g->maxfrozen remain.
+ *
+ * return true if any frozen peers are removed.
+ */
+static bool delete_old_frozen(Group_c *g)
+{
+    if (g->numfrozen <= g->maxfrozen) {
+        return false;
+    }
+
+    if (g->maxfrozen == 0) {
+        free(g->frozen);
+        g->frozen = nullptr;
+        g->numfrozen = 0;
+        return true;
+    }
+
+    qsort(g->frozen, g->numfrozen, sizeof(Group_Peer), cmp_frozen);
+
+    Group_Peer *temp = (Group_Peer *)realloc(g->frozen, sizeof(Group_Peer) * g->maxfrozen);
+
+    if (temp == nullptr) {
+        return false;
+    }
+
+    g->frozen = temp;
+
+    g->numfrozen = g->maxfrozen;
+
+    return true;
+}
+
 static bool try_send_rejoin(Group_Chats *g_c, uint32_t groupnumber, const uint8_t *real_pk);
 
 static int freeze_peer(Group_Chats *g_c, uint32_t groupnumber, int peer_index, void *userdata)
@@ -762,8 +814,6 @@ static int freeze_peer(Group_Chats *g_c, uint32_t groupnumber, int peer_index, v
         return -1;
     }
 
-    try_send_rejoin(g_c, groupnumber, g->group[peer_index].real_pk);
-
     Group_Peer *temp = (Group_Peer *)realloc(g->frozen, sizeof(Group_Peer) * (g->numfrozen + 1));
 
     if (temp == nullptr) {
@@ -773,9 +823,18 @@ static int freeze_peer(Group_Chats *g_c, uint32_t groupnumber, int peer_index, v
     g->frozen = temp;
     g->frozen[g->numfrozen] = g->group[peer_index];
     g->frozen[g->numfrozen].object = nullptr;
+
+    if (delpeer(g_c, groupnumber, peer_index, userdata, true) != 0) {
+        return -1;
+    }
+
+    try_send_rejoin(g_c, groupnumber, g->frozen[g->numfrozen].real_pk);
+
     ++g->numfrozen;
 
-    return delpeer(g_c, groupnumber, peer_index, userdata, true);
+    delete_old_frozen(g);
+
+    return 0;
 }
 
 
@@ -1236,6 +1295,24 @@ int group_frozen_last_active(const Group_Chats *g_c, uint32_t groupnumber, int p
     return 0;
 }
 
+/* Set maximum number of frozen peers.
+ *
+ * return 0 on success.
+ * return -1 if groupnumber is invalid.
+ */
+int group_set_max_frozen(const Group_Chats *g_c, uint32_t groupnumber, uint32_t maxfrozen)
+{
+    Group_c *g = get_group_c(g_c, groupnumber);
+
+    if (!g) {
+        return -1;
+    }
+
+    g->maxfrozen = maxfrozen;
+    delete_old_frozen(g);
+    return 0;
+}
+
 /* List all the (frozen, if frozen is true) peers in the group chat.
  *
  * Copies the names of the peers to the name[length][MAX_NAME_LENGTH] array.
@@ -3208,10 +3285,12 @@ static State_Load_Status load_conferences(Group_Chats *g_c, const uint8_t *data,
         lendian_bytes_to_host32(&g->numfrozen, data);
         data += sizeof(uint32_t);
 
-        g->frozen = (Group_Peer *)malloc(sizeof(Group_Peer) * g->numfrozen);
+        if (g->numfrozen > 0) {
+            g->frozen = (Group_Peer *)malloc(sizeof(Group_Peer) * g->numfrozen);
 
-        if (g->frozen == nullptr) {
-            return STATE_LOAD_STATUS_ERROR;
+            if (g->frozen == nullptr) {
+                return STATE_LOAD_STATUS_ERROR;
+            }
         }
 
         g->title_len = *data;
@@ -3252,6 +3331,13 @@ static State_Load_Status load_conferences(Group_Chats *g_c, const uint8_t *data,
 
             memcpy(peer->nick, data, peer->nick_len);
             data += peer->nick_len;
+
+            // NOTE: this relies on friends being loaded before conferences.
+            peer->is_friend = (getfriend_id(g_c->m, peer->real_pk) != -1);
+        }
+
+        if (g->numfrozen > g->maxfrozen) {
+            g->maxfrozen = g->numfrozen;
         }
 
         g->status = GROUPCHAT_STATUS_CONNECTED;
diff --git a/toxcore/group.h b/toxcore/group.h
index 83015273..884ac8f5 100644
--- a/toxcore/group.h
+++ b/toxcore/group.h
@@ -50,6 +50,7 @@ typedef struct Group_Peer {
     uint8_t     real_pk[CRYPTO_PUBLIC_KEY_SIZE];
     uint8_t     temp_pk[CRYPTO_PUBLIC_KEY_SIZE];
     bool        temp_pk_updated;
+    bool        is_friend;
 
     uint64_t    last_active;
 
@@ -106,6 +107,9 @@ typedef void peer_on_join_cb(void *object, uint32_t conference_number, uint32_t
 typedef void peer_on_leave_cb(void *object, uint32_t conference_number, void *peer_object);
 typedef void group_on_delete_cb(void *object, uint32_t conference_number);
 
+// maximum number of frozen peers to store; group_set_max_frozen() overrides.
+#define MAX_FROZEN_DEFAULT 128
+
 typedef struct Group_c {
     uint8_t status;
 
@@ -118,6 +122,8 @@ typedef struct Group_c {
     Group_Peer *frozen;
     uint32_t numfrozen;
 
+    uint32_t maxfrozen;
+
     /* TODO(zugz) rename close to something more accurate - "connected"? */
     Groupchat_Close close[MAX_GROUP_CONNECTIONS];
 
@@ -284,6 +290,13 @@ int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber,
 int group_frozen_last_active(const Group_Chats *g_c, uint32_t groupnumber, int peernumber,
                              uint64_t *last_active);
 
+/* Set maximum number of frozen peers.
+ *
+ * return 0 on success.
+ * return -1 if groupnumber is invalid.
+ */
+int group_set_max_frozen(const Group_Chats *g_c, uint32_t groupnumber, uint32_t maxfrozen);
+
 /* invite friendnumber to groupnumber
  *
  * return 0 on success.
diff --git a/toxcore/tox.api.h b/toxcore/tox.api.h
index 2e5c7841..51a6d639 100644
--- a/toxcore/tox.api.h
+++ b/toxcore/tox.api.h
@@ -2375,6 +2375,17 @@ namespace conference {
   }
 
   /**
+   * Set maximum number of offline peers to store, overriding the default.
+   */
+  bool set_max_offline(uint32_t conference_number, uint32_t max_offline_peers) {
+    /**
+     * The conference number passed did not designate a valid conference.
+     */
+    CONFERENCE_NOT_FOUND,
+  }
+
+
+  /**
    * Invites a friend to a conference.
    *
    * We must be connected to the conference, meaning that the conference has not
@@ -2806,6 +2817,7 @@ typedef TOX_ERR_FILE_SEND_CHUNK Tox_Err_File_Send_Chunk;
 typedef TOX_ERR_CONFERENCE_NEW Tox_Err_Conference_New;
 typedef TOX_ERR_CONFERENCE_DELETE Tox_Err_Conference_Delete;
 typedef TOX_ERR_CONFERENCE_PEER_QUERY Tox_Err_Conference_Peer_Query;
+typedef TOX_ERR_CONFERENCE_SET_MAX_OFFLINE Tox_Err_Conference_Set_Max_Offline;
 typedef TOX_ERR_CONFERENCE_BY_ID Tox_Err_Conference_By_Id;
 typedef TOX_ERR_CONFERENCE_BY_UID Tox_Err_Conference_By_Uid;
 typedef TOX_ERR_CONFERENCE_INVITE Tox_Err_Conference_Invite;
diff --git a/toxcore/tox.c b/toxcore/tox.c
index d59094af..0a575dbf 100644
--- a/toxcore/tox.c
+++ b/toxcore/tox.c
@@ -1742,6 +1742,22 @@ uint64_t tox_conference_offline_peer_get_last_active(const Tox *tox, uint32_t co
     return last_active;
 }
 
+bool tox_conference_set_max_offline(Tox *tox, uint32_t conference_number,
+                                    uint32_t max_offline_peers,
+                                    Tox_Err_Conference_Set_Max_Offline *error)
+{
+    const Messenger *m = tox->m;
+    const int ret = group_set_max_frozen(m->conferences_object, conference_number, max_offline_peers);
+
+    if (ret == -1) {
+        SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_SET_MAX_OFFLINE_CONFERENCE_NOT_FOUND);
+        return false;
+    }
+
+    SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_SET_MAX_OFFLINE_OK);
+    return true;
+}
+
 bool tox_conference_invite(Tox *tox, uint32_t friend_number, uint32_t conference_number,
                            Tox_Err_Conference_Invite *error)
 {
diff --git a/toxcore/tox.h b/toxcore/tox.h
index 30ae7187..ad66305f 100644
--- a/toxcore/tox.h
+++ b/toxcore/tox.h
@@ -2673,6 +2673,27 @@ bool tox_conference_offline_peer_get_public_key(const Tox *tox, uint32_t confere
 uint64_t tox_conference_offline_peer_get_last_active(const Tox *tox, uint32_t conference_number,
         uint32_t offline_peer_number, TOX_ERR_CONFERENCE_PEER_QUERY *error);
 
+typedef enum TOX_ERR_CONFERENCE_SET_MAX_OFFLINE {
+
+    /**
+     * The function returned successfully.
+     */
+    TOX_ERR_CONFERENCE_SET_MAX_OFFLINE_OK,
+
+    /**
+     * The conference number passed did not designate a valid conference.
+     */
+    TOX_ERR_CONFERENCE_SET_MAX_OFFLINE_CONFERENCE_NOT_FOUND,
+
+} TOX_ERR_CONFERENCE_SET_MAX_OFFLINE;
+
+
+/**
+ * Set maximum number of offline peers to store, overriding the default.
+ */
+bool tox_conference_set_max_offline(Tox *tox, uint32_t conference_number, uint32_t max_offline_peers,
+                                    TOX_ERR_CONFERENCE_SET_MAX_OFFLINE *error);
+
 typedef enum TOX_ERR_CONFERENCE_INVITE {
 
     /**
@@ -3191,6 +3212,7 @@ typedef TOX_ERR_FILE_SEND_CHUNK Tox_Err_File_Send_Chunk;
 typedef TOX_ERR_CONFERENCE_NEW Tox_Err_Conference_New;
 typedef TOX_ERR_CONFERENCE_DELETE Tox_Err_Conference_Delete;
 typedef TOX_ERR_CONFERENCE_PEER_QUERY Tox_Err_Conference_Peer_Query;
+typedef TOX_ERR_CONFERENCE_SET_MAX_OFFLINE Tox_Err_Conference_Set_Max_Offline;
 typedef TOX_ERR_CONFERENCE_BY_ID Tox_Err_Conference_By_Id;
 typedef TOX_ERR_CONFERENCE_BY_UID Tox_Err_Conference_By_Uid;
 typedef TOX_ERR_CONFERENCE_INVITE Tox_Err_Conference_Invite;