baseline: OpenMU upstream b5a0961 (fresh source)

src/GameServer/RemoteView/Guild/BaseGuildInfoPlugIn.cs

@@ -0,0 +1,92 @@
+// <copyright file="BaseGuildInfoPlugIn.cs" company="MUnique">
+// Licensed under the MIT License. See LICENSE file in the project root for full license information.
+// </copyright>
+
+namespace MUnique.OpenMU.GameServer.RemoteView.Guild;
+
+using System.Collections.Concurrent;
+using MUnique.OpenMU.GameLogic;
+using MUnique.OpenMU.GameLogic.Views.Guild;
+using MUnique.OpenMU.Interfaces;
+
+/// <summary>
+/// Abstract base class for a <see cref="IShowGuildInfoPlugIn" /> which allows to cache serialized guild infos.
+/// </summary>
+/// <typeparam name="T">The type of the actual <see cref="IShowGuildInfoPlugIn"/>. Required, so there is one cache per type.</typeparam>
+// ReSharper disable once UnusedTypeParameter we just use it to get type specific static fields.
+public abstract class BaseGuildInfoPlugIn<T>
+{
+    /// <summary>
+    /// The cache for already serialized guilds. This data doesn't change, but is requested often.
+    /// </summary>
+    // ReSharper disable once StaticMemberInGenericType That's what we want
+    private static readonly ConcurrentDictionary<uint, Memory<byte>> Cache = new();
+
+    // ReSharper disable once StaticMemberInGenericType That's what we want
+    private static readonly HashSet<IGameServerContext> AppendedGuildDeletedSenders = new();
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="BaseGuildInfoPlugIn{T}"/> class.
+    /// </summary>
+    /// <param name="player">The player.</param>
+    protected BaseGuildInfoPlugIn(RemotePlayer player)
+    {
+        this.Player = player;
+        lock (AppendedGuildDeletedSenders)
+        {
+            if (AppendedGuildDeletedSenders.Add(player.GameServerContext))
+            {
+                // to make sure we just add one event handler
+                this.Player.GameServerContext.GuildDeleted += OnGuildChanged;
+                this.Player.GameServerContext.GuildChanged += OnGuildChanged;
+            }
+        }
+    }
+
+    /// <summary>
+    /// Gets the player.
+    /// </summary>
+    /// <value>
+    /// The player.
+    /// </value>
+    protected RemotePlayer Player { get; }
+
+    /// <summary>
+    /// Serializes the specified guild.
+    /// </summary>
+    /// <param name="guild">The guild.</param>
+    /// <param name="guildId">The guild identifier.</param>
+    /// <returns>The serialized guild data packet.</returns>
+    protected abstract Memory<byte> Serialize(Guild guild, uint guildId);
+
+    /// <summary>
+    /// Returns the Guild Info Data of a Guild. It will either
+    /// take the data out of the Cache, or get it from the database and serializes it.
+    /// </summary>
+    /// <param name="guildId">The id of the guild.</param>
+    /// <returns>
+    /// The data of the guild.
+    /// </returns>
+    protected async ValueTask<Memory<byte>> GetGuildDataAsync(uint guildId)
+    {
+        if (Cache.TryGetValue(guildId, out var guildInfo))
+        {
+            return guildInfo;
+        }
+
+        var guild = await this.Player.GameServerContext.GuildServer.GetGuildAsync(guildId).ConfigureAwait(false);
+        if (guild is null)
+        {
+            return Memory<byte>.Empty;
+        }
+
+        var data = this.Serialize(guild, guildId);
+        Cache.TryAdd(guildId, data);
+        return data;
+    }
+
+    private static void OnGuildChanged(object? sender, GuildEventArgs args)
+    {
+        Cache.TryRemove(args.GuildId, out _);
+    }
+}