Clear and reuse NodeSet

Author: eelstork

README.md

@@ -94,7 +94,7 @@ Parametric actions are supported; they are concise and type safe. Check the [Bak
 
 Quick and simple Unity integration via [GameAI.cs](Runtime/GameAI.cs) - for details, [read here](Documentation/BakerUnity.md).
 
-Ready to GOAP? [follow the guide](Documentation/Overview.md).
+Ready to GOAP? [Follow the guide](Documentation/Overview.md).
 
 ## Getting involved
 

Runtime/Details/NodeSet.cs

@@ -12,39 +12,34 @@ public class NodeSet<T> : Base{
     HashSet<T>     states = new HashSet<T>();
     List<Node<T>>  list   = new List<Node<T>>();
 
-    public NodeSet(T x, Heuristic<T> h, bool sorted  = true,
-                                        int  capacity = 128,
-                                        float precision = 0){
+    public NodeSet(){}
+
+    public NodeSet<T> Init(T x, Heuristic<T> h, bool sorted  = true,
+                                                int  capacity = 128,
+                                                float precision = 0){
+        if(visited > 0 || count > 0)
+            throw new Exception("Clear NodeSet first");
         this.h = h;
         this.sorted    = sorted;
         this.capacity  = capacity;
         this.precision = precision;
         states.Add(Assert(x, "Initial state"));
         list.Add(new Node<T>(INITIAL_STATE, x));
+        return this;
     }
 
-    public bool capacityExceeded => count > capacity;
-
     public static implicit operator bool(NodeSet<T> self)
     => self.count > 0 && self.count <= self.capacity;
 
-    internal int count => list.Count;
+    public bool capacityExceeded => count > capacity;
+    public int  visited          => states.Count;
+    public int  count            => list.Count;
 
     public bool Insert(Node<T> n){
         if(!states.Add(n.state)) return false;
         if(sorted){
             n.value = n.cost + (h != null ? h(n.state) : 0);
             if(precision > 0) n.value = (int)(n.value / precision);
-            // NOTE: In actual use, tested 4x faster than SortedSet;
-            //  Likely bottleneck with SortedSet is the API, not the
-            // algorithm; SortedSet needs total, ordering:
-            // - a.CompareTo(a) == 0
-            // - a.CompareTo(b) must positive if b.CompareTo(a) is
-            // negative.
-            // Superficially these rules are sound. In practice to
-            // just order elements by cost, this is overkill.
-            // Also getting Min/Max item is cheap, but there's no way
-            // to combine this with a 'pop'
             for(int i = list.Count-1; i >= 0; i--){
                 if(n.value <= list[i].value){
                     list.Insert(i + 1, n);
@@ -55,8 +50,12 @@ public bool Insert(Node<T> n){
     }
 
     public Node<T> Pop(){
-        int i = list.Count-1; var n = list[i]; list.RemoveAt(i);
+        int i = list.Count-1;
+        var n = list[i];
+        list.RemoveAt(i);
         return n;
     }
 
+    public void Clear(){ states.Clear(); list.Clear(); }
+
 }}

Runtime/Solver.cs

@@ -17,7 +17,7 @@ public class Solver<T> : SolverStats where T : class{
     T           initialState;
     Dish<T>     dish;
     Goal<T>     goal;
-    NodeSet<T>  avail = null;
+    NodeSet<T>  avail = new NodeSet<T>();
 
     public bool isRunning => status == S.Running;
 
@@ -27,8 +27,7 @@ public Node<T> Next(T s, in Goal<T> goal, int cap=-1){
         initialState = s;
         this.goal    = goal;
         iteration    = 0;
-        avail        = new NodeSet<T>(s, goal.h, !brfs, maxNodes,
-                                                        tolerance);
+        avail.Init(s, goal.h, !brfs, maxNodes, tolerance);
         return Iterate(cap);
     }
 
@@ -41,19 +40,18 @@ public Node<T> Iterate(int cap=-1){
             var current = avail.Pop();
             if(goal.match(current.state)){
                 status = S.Done;
+                avail.Clear();
                 return current;
             }
             ExpandActions(current, avail);
             ExpandMethods(current, avail);
             if(avail.count > peak) peak = avail.count;
         }
-        if(avail.capacityExceeded){
-            status = S.CapacityExceeded;
-        }else{
-            status = avail
+        status = avail.capacityExceeded ? S.CapacityExceeded
+        : status = avail
             ? (iteration < maxIter ? S.Running : S.MaxIterExceeded)
             : S.Failed;
-        }
+        if(status != S.Running) avail.Clear();
         return null;
     }
 

Tests/Editor/NodeSetTest.cs

@@ -9,17 +9,22 @@ public class NodeSetTest : TestBase{
     Idler idler = new Idler();
 
     [SetUp] public void Setup()
-    => x = new NodeSet<Idler>(idler, null);
+    => x = new NodeSet<Idler>().Init(idler, null);
+
+    [Test] public void NeedsClearBeforeInit()
+    => Assert.Throws<Exception>( () => x.Init(idler, null) );
 
     [Test] public void InitStateMustExist ()
     => Assert.Throws<NullReferenceException>(
-                    () => new NodeSet<Idler>(null, null));
+                    () => new NodeSet<Idler>().Init(null, null));
 
     [Test] public void TrueWithinCapacity()
     { if(x){ } else Assert.Fail(); }
 
-    [Test] public void FalseOverCapacity()
-    { o((bool)new NodeSet<Idler>(idler, null, capacity: 0), false); }
+    [Test] public void FalseOverCapacity(){
+        o((bool)new NodeSet<Idler>().Init(idler, null, capacity: 0),
+          false);
+      }
 
     [Test] public void FalseWhenEmpty()
     { x.Pop(); o( (bool)x, false); }
@@ -28,20 +33,30 @@ [Test] public void InsertAndSkipExisting()
     { x.Insert(new Node<Idler>("x", idler)); o( x.count, 1); }
 
     [Test] public void InsertUnsorted(){
-        var z = new NodeSet<T>(new T(), null);
+        var z = newWith_T;
         z.sorted = false;
-        z.Insert(new Node<T>("x", new T())); o( z.count, 2);
+        z.Insert(newNode_T); o( z.count, 2);
     }
 
     [Test] public void InsertAndSort(){
-        var z = new NodeSet<T>(new T(), null);
-        z.Insert(new Node<T>("x", new T())); o( z.count, 2); }
+        var z = newWith_T;
+        z.Insert(newNode_T); o( z.count, 2); }
 
     [Test] public void Pop(){
         var z = x.Pop(); o( x.count, 0 ); o( z.state is Idler );
         o( z.action, INITIAL_STATE);
     }
 
+    [Test] public void Clear(){
+        var z = newWith_T;
+        o( z.count, 1 ); o( z.visited, 1 );
+        x.Clear();
+        o( x.count, 0 ); o( x.visited, 0 );
+    }
+
+    NodeSet<T> newWith_T => new NodeSet<T>().Init(new T(), null);
+    Node<T>    newNode_T => new Node<T>("x", new T());
+
     class T{
         int x = 0; public T() {} public T(int x){ this.x = x; }
     }