Defer work in vessel modules until the data is actually needed

Source/DynamicBatteryStorage/Data/VesselDataManager.cs

@@ -1,4 +1,5 @@
 using System;
+using UnityEngine;
 
 namespace DynamicBatteryStorage
 {
@@ -7,74 +8,85 @@ namespace DynamicBatteryStorage
   /// </summary>
   public class VesselDataManager : VesselModule
   {
-    #region Accessors
+    public VesselElectricalData ElectricalData => GetElectricalData();
 
-    public VesselElectricalData ElectricalData { get { return electricalData; } }
-    public bool Ready { get { return dataReady; } }
-
-    #endregion
+    VesselElectricalData electricalData;
 
-    #region PrivateVariables
+    VesselElectricalData GetElectricalData()
+    {
+      if (electricalData != null)
+        return electricalData;
 
-    bool dataReady = false;
-    bool vesselLoaded = false;
+      try
+      {
+        RefreshVesselData();
+      }
+      catch (Exception e)
+      {
+        Utils.Error("RefreshVesselData threw an exception");
+        Debug.LogException(e);
+        return null;
+      }
 
-    VesselElectricalData electricalData;
-    #endregion
+      return electricalData;
+    }
 
-    protected override void OnStart()
+    // This module is only active in the flight scene for loaded vessels.
+    public override bool ShouldBeActive()
     {
-      base.OnStart();
+      if (!HighLogic.LoadedSceneIsFlight)
+        return false;
 
-      // These events need to trigger a refresh
-      GameEvents.onVesselGoOnRails.Add(new EventData<Vessel>.OnEvent(RefreshVesselData));
-      GameEvents.onVesselWasModified.Add(new EventData<Vessel>.OnEvent(RefreshVesselData));
+      return vessel.loaded;
     }
 
-    void OnDestroy()
+    // Use OnEnable and OnDisable because ShouldBeActive will cause us to switch
+    // between being enabled and disabled in response to events.
+    void OnEnable()
     {
-      // Clean up events when the item is destroyed
-      GameEvents.onVesselGoOnRails.Remove(RefreshVesselData);
-      GameEvents.onVesselWasModified.Remove(RefreshVesselData);
+      GameEvents.onVesselGoOnRails.Add(RefreshVesselData);
+      GameEvents.onVesselWasModified.Add(InvalidateVesselData);
+
+      if (vessel == FlightGlobals.ActiveVessel)
+        RefreshVesselData();
     }
 
-    void FixedUpdate()
+    void OnDisable()
     {
-      if (HighLogic.LoadedSceneIsFlight && !dataReady)
-      {
-        if (!vesselLoaded && FlightGlobals.ActiveVessel == vessel)
-        {
-          RefreshVesselData();
-          vesselLoaded = true;
-        }
-        if (vesselLoaded && FlightGlobals.ActiveVessel != vessel)
-        {
-          vesselLoaded = false;
-        }
-      }
+      GameEvents.onVesselGoOnRails.Remove(RefreshVesselData);
+      GameEvents.onVesselWasModified.Remove(InvalidateVesselData);
+
+      electricalData = null;
     }
 
     /// <summary>
     /// Referesh the data, given a Vessel event
     /// </summary>
     protected void RefreshVesselData(Vessel eventVessel)
     {
-      if (vessel != null && vessel.loaded)
-      {
-        Utils.Log(String.Format("[{0}]: Refreshing VesselData from Vessel event", this.GetType().Name), Utils.LogType.VesselData);
-        RefreshVesselData();
-      }
+      if (vessel != eventVessel)
+        return;
+      if (vessel == null || !vessel.loaded)
+        return;
+
+      if (Settings.DebugVesselData)
+        Utils.Log($"[{GetType().Name}]: Refreshing VesselData from Vessel event", Utils.LogType.VesselData);
+      RefreshVesselData();
     }
+
     /// <summary>
-    /// Referesh the data, given a ConfigNode event
+    /// Invalidate the current electrical data, given a vessel event.
     /// </summary>
-    protected void RefreshVesselData(ConfigNode node)
+    /// <param name="eventVessel"></param>
+    protected void InvalidateVesselData(Vessel eventVessel)
     {
-      if (vessel != null && vessel.loaded)
-      {
-        Utils.Log(String.Format("[{0}]: Refreshing VesselData from save node event", this.GetType().Name), Utils.LogType.VesselData);
-        RefreshVesselData();
-      }
+      if (vessel != eventVessel)
+        return;
+
+      electricalData = null;
+
+      if (Settings.DebugVesselData)
+        Utils.Log($"[{GetType().Name}]: Invalidated VesselData from Vessel event", Utils.LogType.VesselData);
     }
 
     /// <summary>
@@ -86,8 +98,9 @@ protected void RefreshVesselData()
         return;
 
       electricalData = new VesselElectricalData(vessel.Parts);
-      dataReady = true;
-      Utils.Log(String.Format("Dumping electrical database: \n{0}", electricalData.ToString()), Utils.LogType.VesselData);
+
+      if (Settings.DebugVesselData)
+        Utils.Log($"Dumping electrical database: \n{electricalData}", Utils.LogType.VesselData);
     }
   }
 }

Source/DynamicBatteryStorage/DynamicBatteryStorage.cs

@@ -1,7 +1,4 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using UnityEngine;
 
 namespace DynamicBatteryStorage
@@ -41,95 +38,88 @@ public class ModuleDynamicBatteryStorage : VesselModule
     PartResource bufferStorage;
     Part bufferPart;
 
-    protected override void OnAwake()
+    // Only run on loaded vessels in the flight scene.
+    public override bool ShouldBeActive()
     {
-      base.OnAwake();
-      enabled = Settings.Enabled;
+      if (!Settings.Enabled)
+        return false;
+
+      if (!HighLogic.LoadedSceneIsFlight)
+        return false;
+
+      return vessel.loaded;
     }
-    public override Activation GetActivation()
+
+    void OnEnabled()
     {
-      if (Settings.Enabled)
-      {
-        return Activation.Always;
-      }
-      else
-        return Activation.Never;
+      GameEvents.onVesselGoOnRails.Add(CalculateElectricalData);
+      GameEvents.onVesselWasModified.Add(InvalidateElectricalData);
     }
-    protected override void OnStart()
-    {
-      base.OnStart();
 
-      if (!Settings.Enabled) return;
+    void OnDisable()
+    {
+      GameEvents.onVesselGoOnRails.Add(CalculateElectricalData);
+      GameEvents.onVesselWasModified.Add(InvalidateElectricalData);
+    }
 
-      bufferScale = Settings.BufferScaling;
-      timeWarpLimit = Settings.TimeWarpLimit;
+    void FixedUpdate()
+    {
+      if (!vesselLoaded)
+      {
+        vesselData = vessel.GetComponentCached(ref vesselData);
+        if (!vesselData)
+        {
+          Utils.Error(CreateVesselLogString("Could not find vessel data manager"));
+          return;
+        }
 
-      GameEvents.onVesselDestroy.Add(new EventData<Vessel>.OnEvent(CalculateElectricalData));
-      GameEvents.onVesselGoOnRails.Add(new EventData<Vessel>.OnEvent(CalculateElectricalData));
-      GameEvents.onVesselWasModified.Add(new EventData<Vessel>.OnEvent(CalculateElectricalData));
+        CalculateElectricalData();
+        vesselLoaded = true;
+      }
 
-      FindDataManager();
+      analyticMode = TimeWarp.CurrentRate < timeWarpLimit;
+      if (!analyticMode)
+        DoLowWarpSimulation();
+      else
+        DoHighWarpSimulation();
     }
 
-    protected override void OnSave(ConfigNode node)
+    protected void InvalidateElectricalData(Vessel eventVessel)
     {
-      // Saving needs to trigger a buffer clear
-      ClearBufferStorage();
-      base.OnSave(node);
-    }
+      if (vessel != eventVessel)
+        return;
 
-    void OnDestroy()
-    {
-      GameEvents.onVesselDestroy.Remove(CalculateElectricalData);
-      GameEvents.onVesselGoOnRails.Remove(CalculateElectricalData);
-      GameEvents.onVesselWasModified.Remove(CalculateElectricalData);
+      vesselLoaded = false;
+      bufferPart = null;
+      bufferStorage = null;
     }
 
-    void FindDataManager()
+    protected void CalculateElectricalData(Vessel eventVessel)
     {
-      vesselData = vessel.GetComponent<VesselDataManager>();
-      if (!vesselData)
-      {
-        Utils.Error(CreateVesselLogString("Could not find vessel data manager"));
-      }
+      if (vessel != eventVessel)
+        return;
+      if (!vessel.loaded)
+        return;
+
+      CalculateElectricalData();
     }
 
-    void FixedUpdate()
+    protected override void OnSave(ConfigNode node)
     {
-      if (HighLogic.LoadedSceneIsFlight)
-      {
-        if (!vesselLoaded && FlightGlobals.ActiveVessel == vessel)
-        {
-          FindDataManager();
-          CalculateElectricalData();
-          vesselLoaded = true;
-        }
-        if (vesselLoaded && FlightGlobals.ActiveVessel != vessel)
-        {
-          vesselLoaded = false;
-        }
-        if (TimeWarp.CurrentRate < timeWarpLimit)
-        {
-          analyticMode = false;
-          DoLowWarpSimulation();
-        }
-        else
-        {
-          analyticMode = true;
-          DoHighWarpSimulation();
-        }
-      }
+      // Saving needs to trigger a buffer clear
+      ClearBufferStorage();
+      base.OnSave(node);
     }
 
     /// <summary>
     /// Runs the compensation at low warp. This typically means do nothing
     /// </summary>
     protected void DoLowWarpSimulation()
     {
-      if (bufferStorage != null && bufferStorage.maxAmount != originalMax)
-      {
-        bufferStorage.maxAmount = originalMax;
-      }
+      if (bufferStorage == null)
+        return;
+
+      bufferStorage.maxAmount = originalMax;
     }
 
     /// <summary>
@@ -202,22 +192,6 @@ protected void CalculateElectricalData()
       }
     }
 
-
-    protected void CalculateElectricalData(Vessel eventVessel)
-    {
-      if (vessel != null && vessel.loaded)
-      {
-        CalculateElectricalData();
-      }
-    }
-    protected void CalculateElectricalData(ConfigNode node)
-    {
-      if (vessel != null && vessel.loaded)
-      {
-        CalculateElectricalData();
-      }
-    }
-
     /// <summary>
     /// Clears the buffer (reverts it to its initial state)
     /// </summary>