db.d: add method for removing all excessive tickers

Author: mathiascode

src/db.d

@@ -7,8 +7,9 @@ module soulfind.db;
 @safe:
 
 import soulfind.defines : blue, default_max_users, default_motd, default_port,
-                          default_private_mode, log_db, norm, RoomMemberType,
-                          RoomTicker, RoomType, SearchFilterType, UserStats;
+                          default_private_mode, log_db, max_room_tickers, norm,
+                          RoomMemberType, RoomTicker, RoomType,
+                          SearchFilterType, UserStats;
 import std.array : Appender;
 import std.conv : ConvException, text, to;
 import std.datetime : Clock, days, Duration, SysTime, UTC;
@@ -1147,19 +1148,30 @@ final class Database
         return true;
     }
 
-    string del_oldest_ticker(string room_name)
+    bool del_excessive_tickers(string room_name)
     {
+        if (num_room_tickers(room_name) <= max_room_tickers)
+            return false;
+
         enum sql = text(
-            "SELECT username FROM ", tickers_table, " WHERE room = ? LIMIT 1;"
+            "DELETE FROM ", tickers_table, " WHERE rowid IN (",
+            " SELECT rowid FROM ", tickers_table,
+            " WHERE room = ?",
+            " ORDER BY rowid DESC",
+            " LIMIT -1 OFFSET ?",
+            ");",
         );
-        const res = query(sql, [room_name]);
-        string username;
+        query(sql, [room_name, max_room_tickers.text]);
 
-        if (res.length > 0) {
-            username = res[0][0];
-            del_ticker(room_name, username);
-        }
-        return username;
+        const num_deleted = changes();
+        if (num_deleted == 0)
+            return false;
+
+        if (log_db) writeln(
+            "[DB] Removed ", num_deleted.text, " excessive tickers from room ",
+            blue, room_name, norm
+        );
+        return true;
     }
 
     RoomTicker[] room_tickers(string room_name)

src/server/room.d

@@ -8,8 +8,7 @@ module soulfind.server.room;
 
 import soulfind.db : Database;
 import soulfind.defines : blue, log_msg, max_chat_message_length,
-                          max_room_ticker_length, max_room_tickers, norm,
-                          RoomTicker, RoomType;
+                          max_room_ticker_length, norm, RoomTicker, RoomType;
 import soulfind.server.conns : Logging;
 import soulfind.server.messages;
 import soulfind.server.user : User;
@@ -148,11 +147,10 @@ final class Room
         enum permanent = false;
         del_ticker(username, permanent);
 
-        if (num_tickers >= max_room_tickers)
-            del_oldest_ticker ();
-
         scope msg = new SRoomTickerAdd(name, username, content);
         send_to_all(msg);
+
+        db.del_excessive_tickers(name);
     }
 
     void del_ticker(string username, bool permanent = true)
@@ -164,21 +162,6 @@ final class Room
         send_to_all(msg);
     }
 
-    ulong num_tickers()
-    {
-        return db.num_room_tickers(name);
-    }
-
-    private void del_oldest_ticker()
-    {
-        const username = db.del_oldest_ticker(name);
-        if (username is null)
-            return;
-
-        scope msg = new SRoomTickerRemove(name, username);
-        send_to_all(msg);
-    }
-
     private RoomTicker[] tickers()
     {
         return db.room_tickers(name);