Add ModelContextProtocol.Core package (#428)

src/ModelContextProtocol.Core/Server/McpServerPrimitiveCollection.cs

@@ -0,0 +1,162 @@
+using System.Collections;
+using System.Collections.Concurrent;
+using System.Diagnostics.CodeAnalysis;
+
+namespace ModelContextProtocol.Server;
+
+/// <summary>Provides a thread-safe collection of <typeparamref name="T"/> instances, indexed by their names.</summary>
+/// <typeparam name="T">Specifies the type of primitive stored in the collection.</typeparam>
+public class McpServerPrimitiveCollection<T> : ICollection<T>, IReadOnlyCollection<T>
+    where T : IMcpServerPrimitive
+{
+    /// <summary>Concurrent dictionary of primitives, indexed by their names.</summary>
+    private readonly ConcurrentDictionary<string, T> _primitives = [];
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="McpServerPrimitiveCollection{T}"/> class.
+    /// </summary>
+    public McpServerPrimitiveCollection()
+    {
+    }
+
+    /// <summary>Occurs when the collection is changed.</summary>
+    /// <remarks>
+    /// By default, this is raised when a primitive is added or removed. However, a derived implementation
+    /// may raise this event for other reasons, such as when a primitive is modified.
+    /// </remarks>
+    public event EventHandler? Changed;
+
+    /// <summary>Gets the number of primitives in the collection.</summary>
+    public int Count => _primitives.Count;
+
+    /// <summary>Gets whether there are any primitives in the collection.</summary>
+    public bool IsEmpty => _primitives.IsEmpty;
+
+    /// <summary>Raises <see cref="Changed"/> if there are registered handlers.</summary>
+    protected void RaiseChanged() => Changed?.Invoke(this, EventArgs.Empty);
+
+    /// <summary>Gets the <typeparamref name="T"/> with the specified <paramref name="name"/> from the collection.</summary>
+    /// <param name="name">The name of the primitive to retrieve.</param>
+    /// <returns>The <typeparamref name="T"/> with the specified name.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="name"/> is <see langword="null"/>.</exception>
+    /// <exception cref="KeyNotFoundException">An primitive with the specified name does not exist in the collection.</exception>
+    public T this[string name]
+    {
+        get
+        {
+            Throw.IfNull(name);
+            return _primitives[name];
+        }
+    }
+
+    /// <summary>Clears all primitives from the collection.</summary>
+    public virtual void Clear()
+    {
+        _primitives.Clear();
+        RaiseChanged();
+    }
+
+    /// <summary>Adds the specified <typeparamref name="T"/> to the collection.</summary>
+    /// <param name="primitive">The primitive to be added.</param>
+    /// <exception cref="ArgumentNullException"><paramref name="primitive"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentException">A primitive with the same name as <paramref name="primitive"/> already exists in the collection.</exception>
+    public void Add(T primitive)
+    {
+        if (!TryAdd(primitive))
+        {
+            throw new ArgumentException($"A primitive with the same name '{primitive.Id}' already exists in the collection.", nameof(primitive));
+        }
+    }
+
+    /// <summary>Adds the specified <typeparamref name="T"/> to the collection.</summary>
+    /// <param name="primitive">The primitive to be added.</param>
+    /// <returns><see langword="true"/> if the primitive was added; otherwise, <see langword="false"/>.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="primitive"/> is <see langword="null"/>.</exception>
+    public virtual bool TryAdd(T primitive)
+    {
+        Throw.IfNull(primitive);
+
+        bool added = _primitives.TryAdd(primitive.Id, primitive);
+        if (added)
+        {
+            RaiseChanged();
+        }
+
+        return added;
+    }
+
+    /// <summary>Removes the specified primitivefrom the collection.</summary>
+    /// <param name="primitive">The primitive to be removed from the collection.</param>
+    /// <returns>
+    /// <see langword="true"/> if the primitive was found in the collection and removed; otherwise, <see langword="false"/> if it couldn't be found.
+    /// </returns>
+    /// <exception cref="ArgumentNullException"><paramref name="primitive"/> is <see langword="null"/>.</exception>
+    public virtual bool Remove(T primitive)
+    {
+        Throw.IfNull(primitive);
+
+        bool removed = ((ICollection<KeyValuePair<string, T>>)_primitives).Remove(new(primitive.Id, primitive));
+        if (removed)
+        {
+            RaiseChanged();
+        }
+
+        return removed;
+    }
+
+    /// <summary>Attempts to get the primitive with the specified name from the collection.</summary>
+    /// <param name="name">The name of the primitive to retrieve.</param>
+    /// <param name="primitive">The primitive, if found; otherwise, <see langword="null"/>.</param>
+    /// <returns>
+    /// <see langword="true"/> if the primitive was found in the collection and return; otherwise, <see langword="false"/> if it couldn't be found.
+    /// </returns>
+    /// <exception cref="ArgumentNullException"><paramref name="name"/> is <see langword="null"/>.</exception>
+    public virtual bool TryGetPrimitive(string name, [NotNullWhen(true)] out T? primitive)
+    {
+        Throw.IfNull(name);
+        return _primitives.TryGetValue(name, out primitive);
+    }
+
+    /// <summary>Checks if a specific primitive is present in the collection of primitives.</summary>
+    /// <param name="primitive">The primitive to search for in the collection.</param>
+    /// <see langword="true"/> if the primitive was found in the collection and return; otherwise, <see langword="false"/> if it couldn't be found.
+    /// <exception cref="ArgumentNullException"><paramref name="primitive"/> is <see langword="null"/>.</exception>
+    public virtual bool Contains(T primitive)
+    {
+        Throw.IfNull(primitive);
+        return ((ICollection<KeyValuePair<string, T>>)_primitives).Contains(new(primitive.Id, primitive));
+    }
+
+    /// <summary>Gets the names of all of the primitives in the collection.</summary>
+    public virtual ICollection<string> PrimitiveNames => _primitives.Keys;
+
+    /// <summary>Creates an array containing all of the primitives in the collection.</summary>
+    /// <returns>An array containing all of the primitives in the collection.</returns>
+    public virtual T[] ToArray() => _primitives.Values.ToArray();
+
+    /// <inheritdoc/>
+    public virtual void CopyTo(T[] array, int arrayIndex)
+    {
+        Throw.IfNull(array);
+
+        _primitives.Values.CopyTo(array, arrayIndex);
+    }
+
+    /// <inheritdoc/>
+    public virtual IEnumerator<T> GetEnumerator()
+    {
+        foreach (var entry in _primitives)
+        {
+            yield return entry.Value;
+        }
+    }
+
+    /// <inheritdoc/>
+    IEnumerator<T> IEnumerable<T>.GetEnumerator() => GetEnumerator();
+
+    /// <inheritdoc/>
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+    /// <inheritdoc/>
+    bool ICollection<T>.IsReadOnly => false;
+}