move classes around, name caches more consistently, add more caches

Catalogger.Backend/Cache/InMemoryCache/InMemoryMemberCache.cs

@@ -0,0 +1,46 @@
+using System.Collections.Concurrent;
+using Remora.Discord.API.Abstractions.Objects;
+using Remora.Rest.Core;
+
+namespace Catalogger.Backend.Cache.InMemoryCache;
+
+public class InMemoryMemberCache : IMemberCache
+{
+    private readonly ConcurrentDictionary<(Snowflake, Snowflake), IGuildMember> _members = new();
+    private readonly ConcurrentDictionary<Snowflake, byte> _guilds = new();
+
+#pragma warning disable CS8619 // Nullability of reference types in value doesn't match target type.
+    public Task<IGuildMember?> TryGetAsync(Snowflake guildId, Snowflake userId) =>
+        _members.TryGetValue((guildId, userId), out var member)
+            ? Task.FromResult(member)
+            : Task.FromResult<IGuildMember?>(null);
+#pragma warning restore CS8619 // Nullability of reference types in value doesn't match target type.
+
+    public Task SetAsync(Snowflake guildId, IGuildMember member)
+    {
+        if (!member.User.IsDefined())
+            throw new CataloggerError("Member with undefined User passed to RedisMemberCache.SetAsync");
+        _members[(guildId, member.User.Value.ID)] = member;
+        return Task.CompletedTask;
+    }
+
+    public async Task SetManyAsync(Snowflake guildId, IReadOnlyList<IGuildMember> members)
+    {
+        foreach (var member in members)
+            await SetAsync(guildId, member);
+    }
+
+    public Task<bool> IsGuildCachedAsync(Snowflake guildId) => Task.FromResult(_guilds.ContainsKey(guildId));
+
+    public Task MarkAsCachedAsync(Snowflake guildId)
+    {
+        _guilds[guildId] = 1;
+        return Task.CompletedTask;
+    }
+
+    public Task MarkAsUncachedAsync(Snowflake guildId)
+    {
+        _guilds.Remove(guildId, out _);
+        return Task.CompletedTask;
+    }
+}