Minor performance improvements

MaxMind.Db.Benchmark/MaxMind.Db.Benchmark.csproj

@@ -18,7 +18,7 @@
     <GenerateAssemblyCopyrightAttribute>false</GenerateAssemblyCopyrightAttribute>
     <GenerateAssemblyVersionAttribute>false</GenerateAssemblyVersionAttribute>
     <GenerateAssemblyFileVersionAttribute>false</GenerateAssemblyFileVersionAttribute>
-    <LangVersion>10.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
     <Nullable>enable</Nullable>
     <AnalysisLevel>latest</AnalysisLevel>
     <EnableNETAnalyzers>true</EnableNETAnalyzers>

MaxMind.Db.Test/GlobalSuppressions.cs

@@ -21,3 +21,25 @@
 [assembly: SuppressMessage("Blocker Code Smell", "S2699:Tests should include assertions", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ThreadingTest.TestManyOpens(MaxMind.Db.FileAccessMode)")]
 [assembly: SuppressMessage("Blocker Code Smell", "S2699:Tests should include assertions", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ThreadingTest.TestParallelFor(MaxMind.Db.FileAccessMode)")]
 [assembly: SuppressMessage("Major Code Smell", "S3881:\"IDisposable\" should be implemented correctly", Justification = "<Pending>", Scope = "type", Target = "~T:MaxMind.Db.Test.Helper.NonSeekableStreamWrapper")]
+
+/* Unmerged change from project 'MaxMind.Db.Test (net6.0)'
+Added:
+[assembly: SuppressMessage("Performance", "CA1861:Avoid constant arrays as arguments", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestIPV4(MaxMind.Db.Reader,System.String)")]
+[assembly: SuppressMessage("Performance", "CA1861:Avoid constant arrays as arguments", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestIPV6(MaxMind.Db.Reader,System.String)")]
+*/
+
+/* Unmerged change from project 'MaxMind.Db.Test (net7.0)'
+Added:
+[assembly: SuppressMessage("Performance", "CA1861:Avoid constant arrays as arguments", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestIPV4(MaxMind.Db.Reader,System.String)")]
+[assembly: SuppressMessage("Performance", "CA1861:Avoid constant arrays as arguments", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestIPV6(MaxMind.Db.Reader,System.String)")]
+*/
+
+/* Unmerged change from project 'MaxMind.Db.Test (net8.0)'
+Added:
+[assembly: SuppressMessage("Performance", "CA1861:Avoid constant arrays as arguments", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestIPV4(MaxMind.Db.Reader,System.String)")]
+[assembly: SuppressMessage("Performance", "CA1861:Avoid constant arrays as arguments", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestIPV6(MaxMind.Db.Reader,System.String)")]
+*/
+[assembly: SuppressMessage("Roslynator", "RCS1047:Non-asynchronous method name should not end with 'Async'.", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.NullStreamThrowsArgumentNullExceptionAsync")]
+[assembly: SuppressMessage("Roslynator", "RCS1047:Non-asynchronous method name should not end with 'Async'.", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestEmptyStreamAsync")]
+[assembly: SuppressMessage("Performance", "CA1861:Avoid constant arrays as arguments", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestIPV4(MaxMind.Db.Reader,System.String)")]
+[assembly: SuppressMessage("Performance", "CA1861:Avoid constant arrays as arguments", Justification = "<Pending>", Scope = "member", Target = "~M:MaxMind.Db.Test.ReaderTest.TestIPV6(MaxMind.Db.Reader,System.String)")]

MaxMind.Db.Test/MaxMind.Db.Test.csproj

@@ -21,7 +21,7 @@
     <GenerateAssemblyCopyrightAttribute>false</GenerateAssemblyCopyrightAttribute>
     <GenerateAssemblyVersionAttribute>false</GenerateAssemblyVersionAttribute>
     <GenerateAssemblyFileVersionAttribute>false</GenerateAssemblyFileVersionAttribute>
-    <LangVersion>10.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
     <Nullable>enable</Nullable>
     <AnalysisLevel>latest</AnalysisLevel>
     <EnableNETAnalyzers>true</EnableNETAnalyzers>

MaxMind.Db.Test/ReaderTest.cs

@@ -530,7 +530,7 @@ private static void TestAddresses(Reader reader, string file, IEnumerable<string
             foreach (var address in singleAddresses)
             {
                 reader.Find<Dictionary<string, object>>(IPAddress.Parse(address))["ip"].Should().Be(
-                    new string(address.ToArray()),
+                    new string([.. address]),
                     $"Did not find expected data record for {address} in {file}");
             }
 

MaxMind.Db/Decoder.cs

@@ -41,7 +41,7 @@ internal sealed class Decoder
         private readonly Buffer _database;
         private readonly long _pointerBase;
         private readonly bool _followPointers;
-        private readonly int[] _pointerValueOffset = { 0, 0, 1 << 11, (1 << 19) + (1 << 11), 0 };
+        private readonly int[] _pointerValueOffset = [0, 0, 1 << 11, (1 << 19) + (1 << 11), 0];
 
         private readonly DictionaryActivatorCreator _dictionaryActivatorCreator;
         private readonly ListActivatorCreator _listActivatorCreator;
@@ -352,9 +352,9 @@ private object DecodeMapToType(
             for (var i = 0; i < size; i++)
             {
                 var key = DecodeKey(offset, out offset);
-                if (constructor.DeserializationParameters.ContainsKey(key))
+                if (constructor.DeserializationParameters.TryGetValue(key, out var v))
                 {
-                    var param = constructor.DeserializationParameters[key];
+                    var param = v;
                     var paramType = param.ParameterType;
                     var value = Decode(paramType, offset, out offset, injectables, network);
                     parameters[param.Position] = value;
@@ -397,10 +397,10 @@ private static void SetInjectables(TypeActivator constructor, object[] parameter
         {
             foreach (var item in constructor.InjectableParameters)
             {
-                if (injectables == null || !injectables.Values.ContainsKey(item.Key))
+                if (injectables == null || !injectables.Values.TryGetValue(item.Key, out var value))
                     throw new DeserializationException($"No injectable value found for {item.Key}");
 
-                parameters[item.Value.Position] = injectables.Values[item.Key];
+                parameters[item.Value.Position] = value;
             }
         }
 

MaxMind.Db/Key.cs

@@ -1,6 +1,6 @@
 namespace MaxMind.Db
 {
-    internal struct Key
+    internal readonly struct Key
     {
         private readonly Buffer buffer;
         private readonly long offset;
@@ -16,7 +16,7 @@ public Key(Buffer buffer, long offset, int size)
             var code = 17;
             for (var i = 0; i < size; i++)
             {
-                code = 31 * code + buffer.ReadOne(offset + i);
+                code = (31 * code) + buffer.ReadOne(offset + i);
             }
             hashCode = code;
         }

MaxMind.Db/MaxMind.Db.csproj

@@ -26,7 +26,7 @@
     <GenerateAssemblyCopyrightAttribute>false</GenerateAssemblyCopyrightAttribute>
     <GenerateAssemblyVersionAttribute>false</GenerateAssemblyVersionAttribute>
     <GenerateAssemblyFileVersionAttribute>false</GenerateAssemblyFileVersionAttribute>
-    <LangVersion>10.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Nullable>enable</Nullable>
     <AnalysisLevel>latest</AnalysisLevel>

MaxMind.Db/Reader.cs

@@ -84,6 +84,12 @@ private struct NetNode
         private const int DataSectionSeparatorSize = 16;
         private readonly Buffer _database;
         private readonly string? _fileName;
+        private readonly long _dataPointerOffset;
+        private readonly int _dbIPVersion;
+        private readonly long _nodeByteSize;
+        private readonly long _nodeCount;
+        private readonly int _recordSize;
+        private readonly long _searchTreeSize;
 
         // The property getter was a hotspot during profiling.
 
@@ -133,7 +139,23 @@ private Reader(Buffer buffer, string? file)
             var start = FindMetadataStart();
             var metaDecode = new Decoder(_database, start);
             Metadata = metaDecode.Decode<Metadata>(start, out _);
+            _dataPointerOffset = Metadata.SearchTreeSize - Metadata.NodeCount;
+            _dbIPVersion = Metadata.IPVersion;
+            _nodeByteSize = Metadata.NodeByteSize;
+            _nodeCount = Metadata.NodeCount;
+            _recordSize = Metadata.RecordSize;
+            _searchTreeSize = Metadata.SearchTreeSize;
             Decoder = new Decoder(_database, Metadata.SearchTreeSize + DataSectionSeparatorSize);
+
+            if (_dbIPVersion ==6)
+            {
+                var node = 0;
+                for (var i = 0; i < 96 && node < _nodeCount; i++)
+                {
+                    node = ReadNode(node, 0);
+                }
+                _ipV4Start = node;
+            }
         }
 
         /// <summary>
@@ -174,24 +196,6 @@ private static Buffer BufferForMode(string file, FileAccessMode mode)
         /// </value>
         public Metadata Metadata { get; }
 
-        private int IPv4Start
-        {
-            get
-            {
-                if (_ipV4Start != 0 || Metadata.IPVersion == 4)
-                {
-                    return _ipV4Start;
-                }
-                var node = 0;
-                for (var i = 0; i < 96 && node < Metadata.NodeCount; i++)
-                {
-                    node = ReadNode(node, 0);
-                }
-                _ipV4Start = node;
-                return node;
-            }
-        }
-
         private Decoder Decoder { get; }
 
         /// <summary>
@@ -254,7 +258,7 @@ private void Dispose(bool disposing)
         /// <returns>Enumerator for all data nodes</returns>
         public IEnumerable<ReaderIteratorNode<T>> FindAll<T>(InjectableValues? injectables = null, int cacheSize = 16384) where T : class
         {
-            var byteCount = Metadata.IPVersion == 6 ? 16 : 4;
+            var byteCount = _dbIPVersion == 6 ? 16 : 4;
             var nodes = new List<NetNode>();
             var root = new NetNode { IPBytes = new byte[byteCount] };
             nodes.Add(root);
@@ -265,7 +269,7 @@ public IEnumerable<ReaderIteratorNode<T>> FindAll<T>(InjectableValues? injectabl
                 nodes.RemoveAt(nodes.Count - 1);
                 while (true)
                 {
-                    if (node.Pointer < Metadata.NodeCount)
+                    if (node.Pointer < _nodeCount)
                     {
                         var ipRight = new byte[byteCount];
                         Array.Copy(node.IPBytes, ipRight, ipRight.Length);
@@ -281,7 +285,7 @@ public IEnumerable<ReaderIteratorNode<T>> FindAll<T>(InjectableValues? injectabl
                     }
                     else
                     {
-                        if (node.Pointer > Metadata.NodeCount)
+                        if (node.Pointer > _nodeCount)
                         {
                             // data node, we are done with this branch
                             if (!dataCache.TryGetValue(node.Pointer, out var data))
@@ -315,7 +319,7 @@ public IEnumerable<ReaderIteratorNode<T>> FindAll<T>(InjectableValues? injectabl
 
         private T ResolveDataPointer<T>(int pointer, InjectableValues? injectables, Network? network) where T : class
         {
-            var resolved = pointer - Metadata.NodeCount + Metadata.SearchTreeSize;
+            var resolved = pointer + _dataPointerOffset;
 
             if (resolved >= _database.Length)
             {
@@ -333,7 +337,7 @@ private int FindAddressInTree(IPAddress address, out int prefixLength)
 
             var bitLength = rawAddress.Length * 8;
             var record = StartNode(bitLength);
-            var nodeCount = Metadata.NodeCount;
+            var nodeCount = _nodeCount;
 
             var i = 0;
             for (; i < bitLength && record < nodeCount; i++)
@@ -342,12 +346,12 @@ private int FindAddressInTree(IPAddress address, out int prefixLength)
                 record = ReadNode(record, bit);
             }
             prefixLength = i;
-            if (record == Metadata.NodeCount)
+            if (record == nodeCount)
             {
                 // record is empty
                 return 0;
             }
-            if (record > Metadata.NodeCount)
+            if (record > nodeCount)
             {
                 // record is a data pointer
                 return record;
@@ -359,9 +363,9 @@ private int StartNode(int bitLength)
         {
             // Check if we are looking up an IPv4 address in an IPv6 tree. If this
             // is the case, we can skip over the first 96 nodes.
-            if (Metadata.IPVersion == 6 && bitLength == 32)
+            if (_dbIPVersion == 6 && bitLength == 32)
             {
-                return IPv4Start;
+                return _ipV4Start;
             }
             // The first node of the tree is always node 0, at the beginning of the
             // value
@@ -395,9 +399,9 @@ private long FindMetadataStart()
 
         private int ReadNode(int nodeNumber, int index)
         {
-            var baseOffset = nodeNumber * Metadata.NodeByteSize;
+            var baseOffset = nodeNumber * _nodeByteSize;
 
-            var size = Metadata.RecordSize;
+            var size = _recordSize;
 
             switch (size)
             {
@@ -425,4 +429,4 @@ private int ReadNode(int nodeNumber, int index)
             throw new InvalidDatabaseException($"Unknown record size: {size}");
         }
     }
-}
+}

releasenotes.md

@@ -6,6 +6,7 @@
   However, if you are using .NET 5.0, the .NET Standard 2.1 target should
   continue working for you.
 * .NET 7.0 and .NET 8.0 have been added as a target.
+* Minor performance improvements.
 
 ## 4.0.0 (2022-02-03) ##