Remove update from DeviceLinkSystem (#37152)

The tick updates were purely used to decrease the invoke counter once per tick. Now instead we just calculate the effective counter value with some trivial math on the tick number. This completely removes the need for an update function.

The relative tick is not stored to map files. If we really need this, we can add a TickOffsetSerializer (similar to TimeOffsetSerializer), but I doubt it matters.

Content.Shared/DeviceLinking/SharedDeviceLinkSystem.cs

@@ -4,6 +4,7 @@ using Content.Shared.DeviceLinking.Events;
 using Content.Shared.DeviceNetwork;
 using Content.Shared.Popups;
 using Robust.Shared.Prototypes;
+using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
 namespace Content.Shared.DeviceLinking;
@@ -14,6 +15,7 @@ public abstract class SharedDeviceLinkSystem : EntitySystem
     [Dependency] private readonly SharedPopupSystem _popupSystem = default!;
     [Dependency] private readonly ISharedAdminLogManager _adminLogger = default!;
     [Dependency] private readonly SharedTransformSystem _transform = default!;
+    [Dependency] private readonly IGameTiming _gameTiming = default!;
 
     public const string InvokedPort = "link_port";
 
@@ -525,4 +527,30 @@ public abstract class SharedDeviceLinkSystem : EntitySystem
         // NOOP on client for the moment.
     }
     #endregion
+
+    /// <summary>
+    /// Gets how many times a <see cref="DeviceLinkSinkComponent"/> has been invoked recently.
+    /// </summary>
+    /// <remarks>
+    /// The return value of this function goes up by one every time a sink is invoked, and goes down by one every tick.
+    /// </remarks>
+    public int GetEffectiveInvokeCounter(DeviceLinkSinkComponent sink)
+    {
+        // Shouldn't be possible but just to be safe.
+        var curTick = _gameTiming.CurTick;
+        if (curTick < sink.InvokeCounterTick)
+            return 0;
+
+        var tickDelta = curTick.Value - sink.InvokeCounterTick.Value;
+        if (tickDelta >= sink.InvokeCounter)
+            return 0;
+
+        return Math.Max(0, sink.InvokeCounter - (int)tickDelta);
+    }
+
+    protected void SetInvokeCounter(DeviceLinkSinkComponent sink, int value)
+    {
+        sink.InvokeCounterTick = _gameTiming.CurTick;
+        sink.InvokeCounter = value;
+    }
 }