Add hashfull in last info command using an approx. value

Aprox: non-default items in the first 1k TT entries
lynx-chess · Sep 12, 2023 · 2f872c1 · 2f872c1
1 parent 47ddffe
commit 2f872c1
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Showing 5 changed files with 27 additions and 3 deletions.
diff --git a/src/Lynx/Model/TranspositionTable.cs b/src/Lynx/Model/TranspositionTable.cs
@@ -207,7 +207,7 @@ public static int PopulatedItemsCount(this TranspositionTable transpositionTable
     }
 
     /// <summary>
-    /// TT occupancy per mill
+    /// Exact TT occupancy per mill
     /// </summary>
     /// <param name="transpositionTable"></param>
     /// <returns></returns>
@@ -216,6 +216,27 @@ public static int PopulatedItemsCount(this TranspositionTable transpositionTable
         ? (int)(1000L * transpositionTable.PopulatedItemsCount() / transpositionTable.LongLength)
         : 0;
 
+    /// <summary>
+    /// Orders of magnitude faster than <see cref="HashfullPermill(TranspositionTableElement[])"/>
+    /// </summary>
+    /// <param name="transpositionTable"></param>
+    /// <returns></returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static int HashfullPermillApprox(this TranspositionTable transpositionTable)
+    {
+        int items = 0;
+        for (int i = 0; i < 1000; ++i)
+        {
+            if (transpositionTable[i].Key != default)
+            {
+                ++items;
+            }
+        }
+
+        //Console.WriteLine($"Real: {HashfullPermill(transpositionTable)}, estimated: {items}");
+        return items;
+    }
+
     [Conditional("DEBUG")]
     internal static void Stats(this TranspositionTable transpositionTable)
     {

diff --git a/src/Lynx/Search/Helpers.cs b/src/Lynx/Search/Helpers.cs
@@ -25,7 +25,7 @@ public class SearchResult
 
     public bool IsCancelled { get; set; }
 
-    public int HashfullPermill { get; set; }
+    public int HashfullPermill { get; set; } = -1;
 
     public SearchResult(Move bestMove, double evaluation, int targetDepth, List<Move> moves, int alpha, int beta, int mate = default)
     {

diff --git a/src/Lynx/Search/IDDFS.cs b/src/Lynx/Search/IDDFS.cs
@@ -170,6 +170,7 @@ public sealed partial class Engine
         finalSearchResult.Nodes = _nodes;
         finalSearchResult.Time = _stopWatch.ElapsedMilliseconds;
         finalSearchResult.NodesPerSecond = Utils.CalculateNps(_nodes, _stopWatch.ElapsedMilliseconds);
+        finalSearchResult.HashfullPermill = _tt.HashfullPermillApprox();
 
         if (isMateDetected && finalSearchResult.Mate + Game.HalfMovesWithoutCaptureOrPawnMove < 96)
         {

diff --git a/src/Lynx/Search/OnlineTablebase.cs b/src/Lynx/Search/OnlineTablebase.cs
@@ -20,7 +20,8 @@ public sealed partial class Engine
                     DepthReached = 0,
                     Nodes = 666,                // In case some guis proritize the info command with biggest depth
                     Time = stopWatch.ElapsedMilliseconds,
-                    NodesPerSecond = 0
+                    NodesPerSecond = 0,
+                    HashfullPermill = _tt.HashfullPermillApprox()
                 };
 
                 await _engineWriter.WriteAsync(InfoCommand.SearchResultInfo(searchResult));

diff --git a/src/Lynx/UCI/Commands/Engine/InfoCommand.cs b/src/Lynx/UCI/Commands/Engine/InfoCommand.cs
@@ -86,6 +86,7 @@ public static string SearchResultInfo(SearchResult searchResult)
             $" nodes {searchResult.Nodes}" +
             $" nps {searchResult.NodesPerSecond}" +
             $" time {searchResult.Time}" +
+            (searchResult.HashfullPermill != -1 ? $" hashfull {searchResult.HashfullPermill}" : string.Empty) +
             $" pv {string.Join(" ", searchResult.Moves.Select(move => move.UCIString()))}";
 #pragma warning restore RCS1214 // Unnecessary interpolated string.
     }