Perf/spec binary search

src/Nethermind/Nethermind.Blockchain/Spec/ChainHeadSpecProvider.cs

@@ -25,6 +25,9 @@ public class ChainHeadSpecProvider : IChainHeadSpecProvider
     {
         private readonly ISpecProvider _specProvider;
         private readonly IBlockFinder _blockFinder;
+        private long _lastHeader = -1;
+        private IReleaseSpec? _headerSpec = null;
+        private readonly object _lock = new();
 
         public ChainHeadSpecProvider(ISpecProvider specProvider, IBlockFinder blockFinder)
         {
@@ -42,6 +45,26 @@ public ChainHeadSpecProvider(ISpecProvider specProvider, IBlockFinder blockFinde
 
         public long[] TransitionBlocks => _specProvider.TransitionBlocks;
 
-        public IReleaseSpec GetSpec() => GetSpec(_blockFinder.FindBestSuggestedHeader()?.Number ?? 0);
+        public IReleaseSpec GetSpec()
+        {
+            long headerNumber = _blockFinder.FindBestSuggestedHeader()?.Number ?? 0;
+            if (headerNumber == _lastHeader)
+            {
+                IReleaseSpec releaseSpec = _headerSpec;
+                if (headerNumber == _lastHeader)
+                {
+                    if (releaseSpec is not null)
+                    {
+                        return releaseSpec;
+                    }
+                }
+            }
+
+            lock (_lock)
+            {
+                _lastHeader = headerNumber;
+                return _headerSpec = GetSpec(headerNumber);
+            }
+        }
     }
 }

src/Nethermind/Nethermind.Specs/ChainSpecStyle/ChainSpecBasedSpecProvider.cs

@@ -18,6 +18,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using Nethermind.Core.Collections;
 using Nethermind.Core.Specs;
 using Nethermind.Int256;
 
@@ -170,28 +171,15 @@ private void BuildTransitions()
 
         public IReleaseSpec GenesisSpec => _transitions.Length == 0 ? null : _transitions[0].Release;
 
-        public IReleaseSpec GetSpec(long blockNumber)
-        {
-            if (_transitions.Length == 0)
-            {
-                return null;
-            }
+        public IReleaseSpec GetSpec(long blockNumber) =>
+            _transitions.TryGetSearchedItem(blockNumber,
+                CompareTransitionOnBlock,
+                out (long BlockNumber, IReleaseSpec Release) transition)
+                ? transition.Release
+                : null;
 
-            IReleaseSpec spec = _transitions[0].Release;
-            for (int i = 1; i < _transitions.Length; i++)
-            {
-                if (blockNumber >= _transitions[i].BlockNumber)
-                {
-                    spec = _transitions[i].Release;
-                }
-                else
-                {
-                    break;
-                }
-            }
-
-            return spec;
-        }
+        private static int CompareTransitionOnBlock(long blockNumber, (long BlockNumber, IReleaseSpec Release) transition) => 
+            blockNumber.CompareTo(transition.BlockNumber);
 
         public long? DaoBlockNumber => _chainSpec.DaoForkBlockNumber;