TranspositionTable tests

* Added tests for TranspositionTable and memory tweaks

Mzinga.Core/AI/GameAI.cs

@@ -103,7 +103,7 @@ public GameAI()
             _transpositionTable = new TranspositionTable();
         }
 
-        public GameAI(MetricWeights metricWeights) : base()
+        public GameAI(MetricWeights metricWeights) : this()
         {
             if (null == metricWeights)
             {

Mzinga.Core/AI/TranspositionTable.cs

@@ -39,7 +39,7 @@ private static int GetCapacity(long sizeInBytes)
                 throw new ArgumentOutOfRangeException("sizeInBytes");
             }
 
-            return 1 + (int)Math.Round(sizeInBytes / (double)EntrySizeInBytes);
+            return 1 + (int)Math.Round(FillFactor * sizeInBytes / EntrySizeInBytes);
         }
 
         private static bool TranspostionTableReplaceEntryPredicate(TranspositionTableEntry existingEntry, TranspositionTableEntry entry)
@@ -73,12 +73,14 @@ private static bool TranspostionTableReplaceEntryPredicate(TranspositionTableEnt
             return false;
         }
 
-        private const long EntrySizeInBytes = (2 * sizeof(int)) // Key pointers x2
-                                            + ((2 * 8 + 4 * 11 + 16 * 9) * sizeof(char)) // Key length (2x Q, 4x B, 16x other)
-                                            + sizeof(int) // Entry pointer
-                                            + TranspositionTableEntry.SizeInBytes; // Entry object
+        private static readonly long EntrySizeInBytes = (2 * IntPtr.Size) // Key pointers x2
+                                                        + ((2 * 8 + 4 * 11 + 16 * 9) * sizeof(char)) // Key length (2x Q, 4x B, 16x other)
+                                                        + IntPtr.Size // Entry pointer
+                                                        + TranspositionTableEntry.SizeInBytes; // Entry object
 
-        private const long DefaultSizeInBytes = 16 * 1024 * 1024;
+        public const long DefaultSizeInBytes = 32 * 1024 * 1024;
+
+        private const double FillFactor = 0.92; // To leave room for unaccounted for overhead and unused dictionary capcacity
     }
 
     public class TranspositionTableEntry
@@ -88,11 +90,11 @@ public class TranspositionTableEntry
         public int Depth;
         public string BestMove;
 
-        public const long SizeInBytes = sizeof(TranspositionTableEntryType)
-                                        + sizeof(double) // Value
-                                        + sizeof(int) // Depth
-                                        + sizeof(int) // BestMove pointer
-                                        + (12 * sizeof(char)); // BestMove length
+        public static readonly long SizeInBytes = sizeof(TranspositionTableEntryType)
+                                                    + sizeof(double) // Value
+                                                    + sizeof(int) // Depth
+                                                    + IntPtr.Size // BestMove pointer
+                                                    + (14 * sizeof(char)); // BestMove length
     }
 
     public enum TranspositionTableEntryType : byte

Mzinga.CoreTest/Mzinga.CoreTest.csproj

@@ -72,6 +72,7 @@
     <Compile Include="..\Mzinga.Core\Properties\SharedInfo.cs">
       <Link>Properties\SharedInfo.cs</Link>
     </Compile>
+    <Compile Include="TranspositionTableTests.cs" />
     <Compile Include="MetricWeightsTests.cs" />
     <Compile Include="GameAITests.cs" />
     <Compile Include="MoveSetTests.cs" />

Mzinga.CoreTest/TranspositionTableTests.cs

@@ -0,0 +1,86 @@
+// 
+// TranspositionTableTests.cs
+//  
+// Author:
+//       Jon Thysell <[email protected]>
+// 
+// Copyright (c) 2017 Jon Thysell <http://jonthysell.com>
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using System;
+using System.Diagnostics;
+using System.Text;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+using Mzinga.Core;
+using Mzinga.Core.AI;
+
+namespace Mzinga.CoreTest
+{
+    [TestClass]
+    public class TranspositionTableTests
+    {
+        [TestMethod]
+        public void TranspositionTable_NewTest()
+        {
+            TranspositionTable tt = new TranspositionTable();
+            Assert.IsNotNull(tt);
+        }
+
+        [TestMethod]
+        public void TranspositionTable_MaxMemoryTest()
+        {
+            long expectedSizeInBytes =TranspositionTable.DefaultSizeInBytes;
+
+            TranspositionTable tt = new TranspositionTable(expectedSizeInBytes);
+            Assert.IsNotNull(tt);
+
+            int count = tt.Capacity;
+
+            long startMemoryUsage = GC.GetTotalMemory(true);
+            for (int i = 0; i < tt.Capacity; i++)
+            {
+                string key = i.ToString().PadLeft(204);
+                tt.Store(key, CreateMaxEntry(i));
+            }
+            long endMemoryUsage = GC.GetTotalMemory(true);
+
+            Assert.AreEqual(tt.Capacity, tt.Count);
+
+            long actualSizeInBytes = endMemoryUsage - startMemoryUsage;
+
+            double usageRatio = actualSizeInBytes / (double)expectedSizeInBytes;
+            Trace.WriteLine(string.Format("Usage: {0} ({1:P2})", actualSizeInBytes, usageRatio));
+
+            Assert.IsTrue(usageRatio - 1.0 <= 0.01, string.Format("Table is too big {0:P2}: {1} bytes (~{2} bytes per entry)", usageRatio, actualSizeInBytes - expectedSizeInBytes, (actualSizeInBytes - expectedSizeInBytes) / tt.Count));
+        }
+
+
+        private TranspositionTableEntry CreateMaxEntry(int id)
+        {
+            TranspositionTableEntry te = new TranspositionTableEntry();
+            te.Depth = 0;
+            te.Type = TranspositionTableEntryType.Exact;
+            te.Value = 0;
+            te.BestMove = id.ToString().PadLeft(14);
+            return te;
+        }
+    }
+}