Rewrite nextFreeId to not use a goto

Author: UnknownShadow200

fCraft/Commands/CpeCommands.cs

@@ -159,8 +159,13 @@ private static void EntityHandler(Player player, CommandReader cmd) {
                     string skinString1 = (cmd.Next() ?? entityName);
                     if (skinString1 != null) skinString1 = ParseSkin(skinString1);
 
-                    entity = Entity.Create(entityName, skinString1, requestedModel, player.World, player.Position, getNewID(player.World));
-                    player.Message("Successfully created entity {0}&S with id:{1} and skin {2}.", entity.Name, entity.ID, entity.Skin, entity.Name);
+                    sbyte newEntityId = Entity.NextFreeID(player.World.Name);
+                    if (newEntityId == Packet.SelfId) {
+                        player.Message("No more free ids left! Remove an entity first.");
+                    } else {
+                        entity = Entity.Create(entityName, skinString1, requestedModel, player.World, player.Position, newEntityId);
+                        player.Message("Successfully created entity {0}&S with id:{1} and skin {2}.", entity.Name, entity.ID, entity.Skin, entity.Name);                        
+                    }
                     break;
                 case "remove":
                     player.Message("{0} was removed from {1}", entity.Name, player.World.Name);
@@ -273,18 +278,6 @@ private static void EntityHandler(Player player, CommandReader cmd) {
             }
         }
 
-        public static sbyte getNewID(World world) {
-            sbyte i = 1;
-        go:
-            foreach (Entity entity in Entity.AllIn(world)) {
-                if (entity.ID == i) {
-                    i++;
-                    goto go;
-                }
-            }
-            return i;
-        }
-
         #endregion
 
         #region ChangeModel

fCraft/World/Entity.cs

@@ -155,7 +155,23 @@ public static void ReloadAll() {
             EntityList.Clear();
             LoadAll();
             SpawnAll();
+        }        
+        
+        public unsafe static sbyte NextFreeID(string world) {
+            byte* used = stackalloc byte[128];
+            for (int i = 0; i < 128; i++)
+                used[i] = 0;
+            
+            foreach (Entity entity in Entity.AllIn(world)) {
+                if (entity.ID >= 0) used[entity.ID] = 1;
+            }
+            
+            for (int i = 0; i <= sbyte.MaxValue; i++ ) {
+            	if (used[i] == 0) return (sbyte)i;
+            }
+            return Packet.SelfId;
         }
+        
 
         public static void SaveAll(bool verbose) {
             try {
@@ -216,7 +232,9 @@ public static void OldLoad() {
                 if (entity.World == null) continue;
 
                 sbyte id;
-                if (!sbyte.TryParse(entityData[3], out id)) { id = CpeCommands.getNewID(world); }
+                if (!sbyte.TryParse(entityData[3], out id)) id = NextFreeID(entity.World);
+                if (id == Packet.SelfId) continue;
+                
                 entity.ID = id;
                 entity.Name = entityData[0] ?? entity.ID.ToString();
                 entity.Skin = entityData[1] ?? entity.Name;