Merge pull request #2 from Open-NET-Libraries/experimental

Experimental

Author: electricessence

.editorconfig

@@ -105,8 +105,8 @@ csharp_prefer_static_local_function = true
 csharp_preferred_modifier_order = public,private,protected,internal,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,volatile,async
 
 # Code-block preferences
-csharp_prefer_braces = when_multiline
-csharp_prefer_simple_using_statement = true
+csharp_prefer_braces = when_multiline:silent
+csharp_prefer_simple_using_statement = true:suggestion
 csharp_style_namespace_declarations = file_scoped:suggestion
 
 # Expression-level preferences
@@ -224,4 +224,14 @@ dotnet_naming_style.begins_with_i.capitalization = pascal_case
 dotnet_diagnostic.IDE0057.severity = silent
 
 dotnet_diagnostic.CS1591.severity = suggestion
-#dotnet_diagnostic.SA0001.severity = suggestion
+csharp_style_prefer_method_group_conversion = true:silent
+csharp_style_prefer_top_level_statements = true:silent
+#dotnet_diagnostic.SA0001.severity = suggestion
+[*.{cs,vb}]
+dotnet_style_coalesce_expression = true:warning
+dotnet_style_operator_placement_when_wrapping = beginning_of_line
+tab_width = 4
+indent_size = 4
+end_of_line = crlf
+dotnet_style_null_propagation = true:warning
+indent_style = tab

Open.Collections.sln

@@ -9,7 +9,12 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Open.Collections.Tests", "t
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Open.Collections.Benchmarking", "benchmarking\Open.Collections.Benchmarking.csproj", "{A3EA31B7-6E9B-4780-808A-BBDF116521EA}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Open.Collections.Trie", "Trie\Open.Collections.Trie.csproj", "{A93C5840-7258-48C6-A223-AADCC29B838B}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Open.Collections.Trie", "Trie\Open.Collections.Trie.csproj", "{A93C5840-7258-48C6-A223-AADCC29B838B}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{EDF93B9B-F566-4ED3-8E50-3BCF1DA520FD}"
+	ProjectSection(SolutionItems) = preProject
+		.editorconfig = .editorconfig
+	EndProjectSection
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution

Trie/ConcurrentTrie.cs

@@ -1,36 +1,57 @@
 using System.Collections.Concurrent;
 using System.Collections.Generic;
-using System.Threading;
 
 namespace Open.Collections;
 
 /// <summary>
 /// A generic Trie collection.
 /// </summary>
 public sealed class ConcurrentTrie<TKey, TValue>
-    : TrieBase<TKey, TValue>
+	: TrieBase<TKey, TValue>
+	where TKey : notnull
 {
-    /// <summary>
-    /// Constructs a <see cref="ConcurrentTrie{TKey, TValue}"/>.
-    /// </summary>
-    public ConcurrentTrie()
-        : base(() => new Node())
-    { }
-
-    private sealed class Node : NodeBase
-    {
-        private ConcurrentDictionary<TKey, ITrieNode<TKey, TValue>>? _children;
-
-        public override ITrieNode<TKey, TValue> GetOrAddChild(TKey key)
-        {
-            var children = LazyInitializer.EnsureInitialized(ref _children, ()=>
-            {
-                var c = new ConcurrentDictionary<TKey, ITrieNode<TKey, TValue>>();
-                Children = c;
-                return c;
-            })!;
-
-            return children.GetOrAdd(key, _ => new Node());
-        }
-    }
+	/// <summary>
+	/// Constructs a <see cref="ConcurrentTrie{TKey, TValue}"/>.
+	/// </summary>
+	public ConcurrentTrie(IEqualityComparer<TKey>? equalityComparer = null)
+		: base(() => new Node(equalityComparer))
+	{ }
+
+	private sealed class Node : NodeBase
+	{
+		public Node(IEqualityComparer<TKey>? equalityComparer)
+			=> _equalityComparer = equalityComparer;
+
+		private readonly object _valueSync = new();
+
+		protected override void SetValue(TValue value)
+		{
+			lock (_valueSync) base.SetValue(value);
+		}
+
+		private readonly object _childSync = new();
+
+		private readonly IEqualityComparer<TKey>? _equalityComparer;
+		private ConcurrentDictionary<TKey, ITrieNode<TKey, TValue>>? _children;
+
+		protected override void UpdateRecent(TKey key, ITrieNode<TKey, TValue> child)
+		{
+			lock (_childSync) base.UpdateRecent(key, child);
+		}
+
+		public override ITrieNode<TKey, TValue> GetOrAddChild(TKey key)
+		{
+			var children = _children;
+			if (children is null)
+			{
+				lock (_childSync)
+				{
+					if (children is null)
+						Children = _children = children = _equalityComparer is null ? new() : new(_equalityComparer);
+				}
+			}
+
+			return children.GetOrAdd(key, _ => new Node(_equalityComparer));
+		}
+	}
 }

Trie/HybridDictionary.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Open.Collections.Trie;
+internal class HybridDictionary<TKey, TValue> : IDictionary<TKey, TValue>
+{
+    private readonly struct Entry
+    {
+        public Entry(TKey key, TValue value)
+        {
+            Key = key;
+            Value = value;
+        }
+
+        public TKey Key { get; }
+        public TValue Value { get; }
+    }
+
+    private const int SEARCH_THRESHOLD = 12;
+
+    private Entry[]? _list;
+    private readonly Dictionary<TKey, TValue> _dictionary;
+
+    public ICollection<TKey> Keys => _dictionary.Keys;
+
+    public ICollection<TValue> Values => _dictionary.Values;
+
+    public int Count => _dictionary.Count;
+
+    public bool IsReadOnly => ((ICollection<KeyValuePair<TKey, TValue>>)_dictionary).IsReadOnly;
+
+    public HybridDictionary()
+    {
+        _list = new Entry[SEARCH_THRESHOLD];
+        _dictionary = new();
+    }
+
+    public TValue this[TKey key]
+    {
+        get => TryGetValue(key, out var value) ? value : throw new KeyNotFoundException();
+        set => Add(key, value);
+    }
+
+    public void Add(TKey key, TValue value)
+    {
+        _dictionary.Add(key, value);
+        int count = _dictionary.Count;
+        var list = _list;
+        if (list is null) return;
+        if (count == SEARCH_THRESHOLD)
+            _list = null;
+        else
+            list[count - 1] = new(key, value);
+    }
+
+    public bool TryGetValue(TKey key, out TValue value)
+    {
+        if (key is null) throw new ArgumentNullException(nameof(key));
+
+        var list = _list;
+        if(list is not null)
+        {
+            foreach(var e in list)
+            {
+                if(key.Equals(e.Key))
+                {
+                    value = e.Value;
+                    return true;
+                }
+            }
+
+            value = default!;
+            return false;
+        }
+
+        return _dictionary.TryGetValue(key, out value);
+    }
+
+    public bool Remove(TKey key) => throw new NotSupportedException();
+
+    public void Clear()
+    {
+        _dictionary.Clear();
+        _list = new Entry[SEARCH_THRESHOLD];
+    }
+
+    public bool ContainsKey(TKey key) => _dictionary.ContainsKey(key);
+    public void Add(KeyValuePair<TKey, TValue> item) => Add(item.Key, item.Value);
+    public bool Contains(KeyValuePair<TKey, TValue> item) => _dictionary.Contains(item);
+    public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex) => ((ICollection<KeyValuePair<TKey, TValue>>)_dictionary).CopyTo(array, arrayIndex);
+    public bool Remove(KeyValuePair<TKey, TValue> item) => throw new NotSupportedException();
+    public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator() => _dictionary.GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => _dictionary.GetEnumerator();
+}