Several performance/memory improvements. Renamed CachedPublicUser -> CachedGlobalUser.

src/Discord.Net/Data/DefaultDataStore.cs

@@ -15,12 +15,12 @@ namespace Discord.Data
         private readonly ConcurrentDictionary<ulong, ICachedChannel> _channels;
         private readonly ConcurrentDictionary<ulong, CachedDMChannel> _dmChannels;
         private readonly ConcurrentDictionary<ulong, CachedGuild> _guilds;
-        private readonly ConcurrentDictionary<ulong, CachedPublicUser> _users;
+        private readonly ConcurrentDictionary<ulong, CachedGlobalUser> _users;
 
         internal override IReadOnlyCollection<ICachedChannel> Channels => _channels.ToReadOnlyCollection();
         internal override IReadOnlyCollection<CachedDMChannel> DMChannels => _dmChannels.ToReadOnlyCollection();
         internal override IReadOnlyCollection<CachedGuild> Guilds => _guilds.ToReadOnlyCollection();
-        internal override IReadOnlyCollection<CachedPublicUser> Users => _users.ToReadOnlyCollection();
+        internal override IReadOnlyCollection<CachedGlobalUser> Users => _users.ToReadOnlyCollection();
 
         public DefaultDataStore(int guildCount, int dmChannelCount)
         {
@@ -29,7 +29,7 @@ namespace Discord.Data
             _channels = new ConcurrentDictionary<ulong, ICachedChannel>(CollectionConcurrencyLevel, (int)(estimatedChannelCount * CollectionMultiplier));
             _dmChannels = new ConcurrentDictionary<ulong, CachedDMChannel>(CollectionConcurrencyLevel, (int)(dmChannelCount * CollectionMultiplier));
             _guilds = new ConcurrentDictionary<ulong, CachedGuild>(CollectionConcurrencyLevel, (int)(guildCount * CollectionMultiplier));
-            _users = new ConcurrentDictionary<ulong, CachedPublicUser>(CollectionConcurrencyLevel, (int)(estimatedUsersCount * CollectionMultiplier));
+            _users = new ConcurrentDictionary<ulong, CachedGlobalUser>(CollectionConcurrencyLevel, (int)(estimatedUsersCount * CollectionMultiplier));
         }
 
         internal override ICachedChannel GetChannel(ulong id)
@@ -94,20 +94,20 @@ namespace Discord.Data
             return null;
         }
 
-        internal override CachedPublicUser GetUser(ulong id)
+        internal override CachedGlobalUser GetUser(ulong id)
         {
-            CachedPublicUser user;
+            CachedGlobalUser user;
             if (_users.TryGetValue(id, out user))
                 return user;
             return null;
         }
-        internal override CachedPublicUser GetOrAddUser(ulong id, Func<ulong, CachedPublicUser> userFactory)
+        internal override CachedGlobalUser GetOrAddUser(ulong id, Func<ulong, CachedGlobalUser> userFactory)
         {
             return _users.GetOrAdd(id, userFactory);
         }
-        internal override CachedPublicUser RemoveUser(ulong id)
+        internal override CachedGlobalUser RemoveUser(ulong id)
         {
-            CachedPublicUser user;
+            CachedGlobalUser user;
             if (_users.TryRemove(id, out user))
                 return user;
             return null;

src/Discord.Net/Data/IDataStore.cs

@@ -8,7 +8,7 @@ namespace Discord.Data
         internal abstract IReadOnlyCollection<ICachedChannel> Channels { get; }
         internal abstract IReadOnlyCollection<CachedDMChannel> DMChannels { get; }
         internal abstract IReadOnlyCollection<CachedGuild> Guilds { get; }
-        internal abstract IReadOnlyCollection<CachedPublicUser> Users { get; }
+        internal abstract IReadOnlyCollection<CachedGlobalUser> Users { get; }
 
         internal abstract ICachedChannel GetChannel(ulong id);
         internal abstract void AddChannel(ICachedChannel channel);
@@ -22,8 +22,8 @@ namespace Discord.Data
         internal abstract void AddGuild(CachedGuild guild);
         internal abstract CachedGuild RemoveGuild(ulong id);
 
-        internal abstract CachedPublicUser GetUser(ulong id);
-        internal abstract CachedPublicUser GetOrAddUser(ulong userId, Func<ulong, CachedPublicUser> userFactory);
-        internal abstract CachedPublicUser RemoveUser(ulong id);
+        internal abstract CachedGlobalUser GetUser(ulong id);
+        internal abstract CachedGlobalUser GetOrAddUser(ulong userId, Func<ulong, CachedGlobalUser> userFactory);
+        internal abstract CachedGlobalUser RemoveUser(ulong id);
     }
 }

src/Discord.Net/DiscordSocketClient.cs

@@ -13,7 +13,6 @@ using System.Collections.Immutable;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
-using System.Diagnostics;
 
 namespace Discord
 {
@@ -51,15 +50,17 @@ namespace Discord
         private readonly bool _enablePreUpdateEvents;
         private readonly int _largeThreshold;
         private readonly int _totalShards;
-        private ConcurrentHashSet<ulong> _dmChannels;
+
         private string _sessionId;
         private int _lastSeq;
         private ImmutableDictionary<string, VoiceRegion> _voiceRegions;
         private TaskCompletionSource<bool> _connectTask;
-        private CancellationTokenSource _heartbeatCancelToken;
-        private Task _heartbeatTask, _reconnectTask;
+        private CancellationTokenSource _cancelToken;
+        private Task _heartbeatTask, _guildDownloadTask, _reconnectTask;
         private long _heartbeatTime;
         private bool _isReconnecting;
+        private int _unavailableGuilds;
+        private long _lastGuildAvailableTime;
 
         /// <summary> Gets the shard if of this client. </summary>
         public int ShardId { get; }
@@ -74,15 +75,7 @@ namespace Discord
 
         internal CachedSelfUser CurrentUser => _currentUser as CachedSelfUser;
         internal IReadOnlyCollection<CachedGuild> Guilds => DataStore.Guilds;
-        internal IReadOnlyCollection<CachedDMChannel> DMChannels
-        {
-            get
-            {
-                var dmChannels = _dmChannels;
-                var store = DataStore;
-                return dmChannels.Select(x => store.GetChannel(x) as CachedDMChannel).Where(x => x != null).ToReadOnlyCollection(dmChannels);
-            }
-        }
+        internal IReadOnlyCollection<CachedDMChannel> DMChannels => DataStore.DMChannels;
         internal IReadOnlyCollection<VoiceRegion> VoiceRegions => _voiceRegions.ToReadOnlyCollection();
 
         /// <summary> Creates a new REST/WebSocket discord client. </summary>
@@ -132,7 +125,6 @@ namespace Discord
 
             _voiceRegions = ImmutableDictionary.Create<string, VoiceRegion>();
             _largeGuilds = new ConcurrentQueue<ulong>();
-            _dmChannels = new ConcurrentHashSet<ulong>();
         }
 
         protected override async Task OnLoginAsync()
@@ -169,10 +161,11 @@ namespace Discord
             try
             {
                 _connectTask = new TaskCompletionSource<bool>();
-                _heartbeatCancelToken = new CancellationTokenSource();
+                _cancelToken = new CancellationTokenSource();
                 await ApiClient.ConnectAsync().ConfigureAwait(false);
 
                 await _connectTask.Task.ConfigureAwait(false);
+                
                 ConnectionState = ConnectionState.Connected;
                 await _gatewayLogger.InfoAsync("Connected");
             }
@@ -203,9 +196,24 @@ namespace Discord
             ConnectionState = ConnectionState.Disconnecting;
             await _gatewayLogger.InfoAsync("Disconnecting");
 
-            try { _heartbeatCancelToken.Cancel(); } catch { }
+            //Signal tasks to complete
+            try { _cancelToken.Cancel(); } catch { }
+
+            //Disconnect from server
             await ApiClient.DisconnectAsync().ConfigureAwait(false);
-            await _heartbeatTask.ConfigureAwait(false);
+
+            //Wait for tasks to complete
+            var heartbeatTask = _heartbeatTask;
+            if (heartbeatTask != null)
+                await heartbeatTask.ConfigureAwait(false);
+            _heartbeatTask = null;
+
+            var guildDownloadTask = _guildDownloadTask;
+            if (guildDownloadTask != null)
+                await guildDownloadTask.ConfigureAwait(false);
+            _guildDownloadTask = null;
+
+            //Clear large guild queue
             while (_largeGuilds.TryDequeue(out guildId)) { }
 
             ConnectionState = ConnectionState.Disconnected;
@@ -216,22 +224,21 @@ namespace Discord
         private async Task StartReconnectAsync()
         {
             //TODO: Is this thread-safe?
-            while (true)
+            await _log.InfoAsync("Debug", "Trying to reconnect...").ConfigureAwait(false);
+            if (_reconnectTask != null) return;
+
+            await _connectionLock.WaitAsync().ConfigureAwait(false);
+            try
             {
                 if (_reconnectTask != null) return;
-
-                await _connectionLock.WaitAsync().ConfigureAwait(false);
-                try
-                {
-                    if (_reconnectTask != null) return;
-                    _isReconnecting = true;
-                    _reconnectTask = ReconnectInternalAsync();
-                }
-                finally { _connectionLock.Release(); }
+                _isReconnecting = true;
+                _reconnectTask = ReconnectInternalAsync();
             }
+            finally { _connectionLock.Release(); }
         }
         private async Task ReconnectInternalAsync()
         {
+            await _log.InfoAsync("Debug", "Reconnecting...").ConfigureAwait(false);
             try
             {
                 int nextReconnectDelay = 1000;
@@ -255,13 +262,18 @@ namespace Discord
                     catch (Exception ex)
                     {
                         await _gatewayLogger.WarningAsync("Reconnect failed", ex).ConfigureAwait(false);
-                    }                }
+                    }
+                }
             }
             finally
             {
-                _isReconnecting = false;
-                _reconnectTask = null;
-
+                await _connectionLock.WaitAsync().ConfigureAwait(false);
+                try
+                {
+                    _isReconnecting = false;
+                    _reconnectTask = null;
+                }
+                finally { _connectionLock.Release(); }
             }
         }
 
@@ -318,20 +330,22 @@ namespace Discord
         {
             return Task.FromResult<IReadOnlyCollection<IDMChannel>>(DMChannels);
         }
-        internal CachedDMChannel AddDMChannel(API.Channel model, DataStore dataStore, ConcurrentHashSet<ulong> dmChannels)
+        internal CachedDMChannel AddDMChannel(API.Channel model, DataStore dataStore)
         {
             var recipient = GetOrAddUser(model.Recipient.Value, dataStore);
-            var channel = recipient.AddDMChannel(this, model);
-            dataStore.AddChannel(channel);
-            dmChannels.TryAdd(model.Id);
+            var channel = new CachedDMChannel(this, new CachedDMUser(recipient), model);
+            recipient.AddRef();
+            dataStore.AddDMChannel(channel);
             return channel;
         }
         internal CachedDMChannel RemoveDMChannel(ulong id)
         {            
-            var dmChannel = DataStore.RemoveChannel(id) as CachedDMChannel;            
-            var recipient = dmChannel.Recipient;
-            recipient.RemoveDMChannel(id);
-            _dmChannels.TryRemove(id);
+            var dmChannel = DataStore.RemoveDMChannel(id);
+            if (dmChannel != null)
+            {
+                var recipient = dmChannel.Recipient;
+                recipient.User.RemoveRef(this);
+            }
             return dmChannel;
         }
 
@@ -345,13 +359,13 @@ namespace Discord
         {
             return Task.FromResult<IUser>(DataStore.Users.Where(x => x.Discriminator == discriminator && x.Username == username).FirstOrDefault());
         }
-        internal CachedPublicUser GetOrAddUser(API.User model, DataStore dataStore)
+        internal CachedGlobalUser GetOrAddUser(API.User model, DataStore dataStore)
         {
-            var user = dataStore.GetOrAddUser(model.Id, _ => new CachedPublicUser(model));
+            var user = dataStore.GetOrAddUser(model.Id, _ => new CachedGlobalUser(model));
             user.AddRef();
             return user;
         }
-        internal CachedPublicUser RemoveUser(ulong id)
+        internal CachedGlobalUser RemoveUser(ulong id)
         {
             return DataStore.RemoveUser(id);
         }
@@ -425,7 +439,7 @@ namespace Discord
                             else
                                 await ApiClient.SendIdentifyAsync().ConfigureAwait(false);
                             _heartbeatTime = 0;
-                            _heartbeatTask = RunHeartbeatAsync(data.HeartbeatInterval, _heartbeatCancelToken.Token);
+                            _heartbeatTask = RunHeartbeatAsync(data.HeartbeatInterval, _cancelToken.Token);
                         }
                         break;
                     case GatewayOpCode.Heartbeat:
@@ -439,12 +453,16 @@ namespace Discord
                         {
                             await _gatewayLogger.DebugAsync("Received HeartbeatAck").ConfigureAwait(false);
 
-                            var latency = (int)(Environment.TickCount - _heartbeatTime);
-                            _heartbeatTime = 0;
-                            await _gatewayLogger.DebugAsync($"Latency = {latency} ms").ConfigureAwait(false);
-                            Latency = latency;
+                            var heartbeatTime = _heartbeatTime;
+                            if (heartbeatTime != 0)
+                            {
+                                var latency = (int)(Environment.TickCount - _heartbeatTime);
+                                _heartbeatTime = 0;
+                                await _gatewayLogger.VerboseAsync($"Latency = {latency} ms").ConfigureAwait(false);
+                                Latency = latency;
 
-                            await LatencyUpdated.RaiseAsync(latency).ConfigureAwait(false);
+                                await LatencyUpdated.RaiseAsync(latency).ConfigureAwait(false);
+                            }
                         }
                         break;
                     case GatewayOpCode.InvalidSession:
@@ -475,21 +493,29 @@ namespace Discord
                                     
                                     var data = (payload as JToken).ToObject<ReadyEvent>(_serializer);
                                     var dataStore = _dataStoreProvider(ShardId, _totalShards, data.Guilds.Length, data.PrivateChannels.Length);
-                                    var dmChannels = new ConcurrentHashSet<ulong>();
 
                                     var currentUser = new CachedSelfUser(this, data.User);
+                                    int unavailableGuilds = 0;
                                     //dataStore.GetOrAddUser(data.User.Id, _ => currentUser);
 
                                     for (int i = 0; i < data.Guilds.Length; i++)
-                                        AddGuild(data.Guilds[i], dataStore);
+                                    {
+                                        var model = data.Guilds[i];
+                                        AddGuild(model, dataStore);
+                                        if (model.Unavailable == true)
+                                            unavailableGuilds++;
+                                    }
                                     for (int i = 0; i < data.PrivateChannels.Length; i++)
-                                        AddDMChannel(data.PrivateChannels[i], dataStore, dmChannels);
+                                        AddDMChannel(data.PrivateChannels[i], dataStore);
 
                                     _sessionId = data.SessionId;
                                     _currentUser = currentUser;
-                                    _dmChannels = dmChannels;
+                                    _unavailableGuilds = unavailableGuilds;
+                                    _lastGuildAvailableTime = Environment.TickCount;
                                     DataStore = dataStore;
 
+                                    _guildDownloadTask = WaitForGuildsAsync(_cancelToken.Token);
+
                                     await Ready.RaiseAsync().ConfigureAwait(false);
 
                                     _connectTask.TrySetResult(true); //Signal the .Connect() call to complete
@@ -503,7 +529,10 @@ namespace Discord
                                     var data = (payload as JToken).ToObject<ExtendedGuild>(_serializer);
 
                                     if (data.Unavailable == false)
+                                    {
                                         type = "GUILD_AVAILABLE";
+                                        _lastGuildAvailableTime = Environment.TickCount;
+                                    }
                                     await _gatewayLogger.DebugAsync($"Received Dispatch ({type})").ConfigureAwait(false);
 
                                     CachedGuild guild;
@@ -511,6 +540,7 @@ namespace Discord
                                     {
                                         guild = AddGuild(data, DataStore);
                                         await JoinedGuild.RaiseAsync(guild).ConfigureAwait(false);
+                                        await _gatewayLogger.InfoAsync($"Joined {data.Name}").ConfigureAwait(false);
                                     }
                                     else
                                     {
@@ -526,7 +556,7 @@ namespace Discord
 
                                     if (data.Unavailable != true)
                                     {
-                                        await _gatewayLogger.InfoAsync($"Connected to {data.Name}").ConfigureAwait(false);
+                                        await _gatewayLogger.VerboseAsync($"Connected to {data.Name}").ConfigureAwait(false);
                                         await GuildAvailable.RaiseAsync(guild).ConfigureAwait(false);
                                     }
                                 }
@@ -564,7 +594,7 @@ namespace Discord
                                             member.User.RemoveRef(this);
 
                                         await GuildUnavailable.RaiseAsync(guild).ConfigureAwait(false);
-                                        await _gatewayLogger.InfoAsync($"Disconnected from {data.Name}").ConfigureAwait(false);
+                                        await _gatewayLogger.VerboseAsync($"Disconnected from {data.Name}").ConfigureAwait(false);
                                         if (data.Unavailable != true)
                                         {
                                             await LeftGuild.RaiseAsync(guild).ConfigureAwait(false);
@@ -587,7 +617,7 @@ namespace Discord
 
                                     var data = (payload as JToken).ToObject<API.Channel>(_serializer);
                                     ICachedChannel channel = null;
-                                    if (data.GuildId.IsSpecified)
+                                    if (!data.IsPrivate)
                                     {
                                         var guild = DataStore.GetGuild(data.GuildId.Value);
                                         if (guild != null)
@@ -599,7 +629,7 @@ namespace Discord
                                         }
                                     }
                                     else
-                                        channel = AddDMChannel(data, DataStore, _dmChannels);
+                                        channel = AddDMChannel(data, DataStore);
                                     if (channel != null)
                                         await ChannelCreated.RaiseAsync(channel).ConfigureAwait(false);
                                 }
@@ -629,7 +659,7 @@ namespace Discord
 
                                     ICachedChannel channel = null;
                                     var data = (payload as JToken).ToObject<API.Channel>(_serializer);
-                                    if (data.GuildId.IsSpecified)
+                                    if (!data.IsPrivate)
                                     {
                                         var guild = DataStore.GetGuild(data.GuildId.Value);
                                         if (guild != null)
@@ -975,9 +1005,9 @@ namespace Discord
                                     }
                                     else
                                     {
-                                        var user = DataStore.GetUser(data.User.Id);
-                                        if (user == null)
-                                            user.Update(data, UpdateSource.WebSocket);
+                                        var channel = DataStore.GetDMChannel(data.User.Id);
+                                        if (channel != null)
+                                            channel.Recipient.Update(data, UpdateSource.WebSocket);
                                     }
                                 }
                                 break;
@@ -1095,22 +1125,37 @@ namespace Discord
         {
             try
             {
-                var state = ConnectionState;
-                while (state == ConnectionState.Connecting || state == ConnectionState.Connected)
+                while (!cancelToken.IsCancellationRequested)
                 {
                     await Task.Delay(intervalMillis, cancelToken).ConfigureAwait(false);
 
                     if (_heartbeatTime != 0) //Server never responded to our last heartbeat
                     {
-                        await _gatewayLogger.WarningAsync("Server missed last heartbeat").ConfigureAwait(false);
-                        await StartReconnectAsync().ConfigureAwait(false);
-                        return;
+                        if (ConnectionState == ConnectionState.Connected && (_guildDownloadTask?.IsCompleted ?? false))
+                        {
+                            await _gatewayLogger.WarningAsync("Server missed last heartbeat").ConfigureAwait(false);
+                            await StartReconnectAsync().ConfigureAwait(false);
+                            return;
+                        }
                     }
-                    _heartbeatTime = Environment.TickCount;
+                    else
+                        _heartbeatTime = Environment.TickCount;
                     await ApiClient.SendHeartbeatAsync(_lastSeq).ConfigureAwait(false);
                 }
             }
             catch (OperationCanceledException) { }
         }
+
+        private async Task WaitForGuildsAsync(CancellationToken cancelToken)
+        {
+            while ((_unavailableGuilds > 0) || (Environment.TickCount - _lastGuildAvailableTime > 2000))
+                await Task.Delay(500, cancelToken).ConfigureAwait(false);
+        }
+        public async Task WaitForGuildsAsync()
+        {
+            var downloadTask = _guildDownloadTask;
+            if (downloadTask != null)
+                await _guildDownloadTask.ConfigureAwait(false);
+        }
     }
 }

src/Discord.Net/Entities/Channels/DMChannel.cs

@@ -14,11 +14,11 @@ namespace Discord
     internal class DMChannel : SnowflakeEntity, IDMChannel
     {
         public override DiscordClient Discord { get; }
-        public User Recipient { get; private set; }
+        public IUser Recipient { get; private set; }
 
         public virtual IReadOnlyCollection<IMessage> CachedMessages => ImmutableArray.Create<IMessage>();
 
-        public DMChannel(DiscordClient discord, User recipient, Model model)
+        public DMChannel(DiscordClient discord, IUser recipient, Model model)
             : base(model.Id)
         {
             Discord = discord;
@@ -30,7 +30,9 @@ namespace Discord
         {
             if (source == UpdateSource.Rest && IsAttached) return;
             
-            Recipient.Update(model.Recipient.Value, UpdateSource.Rest);
+            //TODO: Is this cast okay?
+            if (Recipient is User)
+                (Recipient as User).Update(model.Recipient.Value, source);
         }
 
         public async Task UpdateAsync()
@@ -119,8 +121,7 @@ namespace Discord
         
         public override string ToString() => '@' + Recipient.ToString();
         private string DebuggerDisplay => $"@{Recipient} ({Id}, DM)";
-
-        IUser IDMChannel.Recipient => Recipient;
+        
         IMessage IMessageChannel.GetCachedMessage(ulong id) => null;
     }
 }

src/Discord.Net/Entities/Channels/GuildChannel.cs

@@ -1,7 +1,5 @@
 using Discord.API.Rest;
-using Discord.Extensions;
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
@@ -14,7 +12,7 @@ namespace Discord
     [DebuggerDisplay(@"{DebuggerDisplay,nq}")]
     internal abstract class GuildChannel : SnowflakeEntity, IGuildChannel
     {
-        private ConcurrentDictionary<ulong, Overwrite> _overwrites;
+        private List<Overwrite> _overwrites; //TODO: Is maintaining a list here too expensive? Is this threadsafe?
 
         public string Name { get; private set; }
         public int Position { get; private set; }
@@ -38,9 +36,9 @@ namespace Discord
             Position = model.Position.Value;
 
             var overwrites = model.PermissionOverwrites.Value;
-            var newOverwrites = new ConcurrentDictionary<ulong, Overwrite>();
+            var newOverwrites = new List<Overwrite>(overwrites.Length);
             for (int i = 0; i < overwrites.Length; i++)
-                newOverwrites[overwrites[i].TargetId] = new Overwrite(overwrites[i]);
+                newOverwrites.Add(new Overwrite(overwrites[i]));
             _overwrites = newOverwrites;
         }
 
@@ -89,16 +87,20 @@ namespace Discord
 
         public OverwritePermissions? GetPermissionOverwrite(IUser user)
         {
-            Overwrite value;
-            if (_overwrites.TryGetValue(user.Id, out value))
-                return value.Permissions;
+            for (int i = 0; i < _overwrites.Count; i++)
+            {
+                if (_overwrites[i].TargetId == user.Id)
+                    return _overwrites[i].Permissions;
+            }
             return null;
         }
         public OverwritePermissions? GetPermissionOverwrite(IRole role)
         {
-            Overwrite value;
-            if (_overwrites.TryGetValue(role.Id, out value))
-                return value.Permissions;
+            for (int i = 0; i < _overwrites.Count; i++)
+            {
+                if (_overwrites[i].TargetId == role.Id)
+                    return _overwrites[i].Permissions;
+            }
             return null;
         }
         
@@ -106,34 +108,46 @@ namespace Discord
         {
             var args = new ModifyChannelPermissionsParams { Allow = perms.AllowValue, Deny = perms.DenyValue };
             await Discord.ApiClient.ModifyChannelPermissionsAsync(Id, user.Id, args).ConfigureAwait(false);
-            _overwrites[user.Id] = new Overwrite(new API.Overwrite { Allow = perms.AllowValue, Deny = perms.DenyValue, TargetId = user.Id, TargetType = PermissionTarget.User });
+            _overwrites.Add(new Overwrite(new API.Overwrite { Allow = perms.AllowValue, Deny = perms.DenyValue, TargetId = user.Id, TargetType = PermissionTarget.User }));
         }
         public async Task AddPermissionOverwriteAsync(IRole role, OverwritePermissions perms)
         {
             var args = new ModifyChannelPermissionsParams { Allow = perms.AllowValue, Deny = perms.DenyValue };
             await Discord.ApiClient.ModifyChannelPermissionsAsync(Id, role.Id, args).ConfigureAwait(false);
-            _overwrites[role.Id] = new Overwrite(new API.Overwrite { Allow = perms.AllowValue, Deny = perms.DenyValue, TargetId = role.Id, TargetType = PermissionTarget.Role });
+            _overwrites.Add(new Overwrite(new API.Overwrite { Allow = perms.AllowValue, Deny = perms.DenyValue, TargetId = role.Id, TargetType = PermissionTarget.Role }));
         }
         public async Task RemovePermissionOverwriteAsync(IUser user)
         {
             await Discord.ApiClient.DeleteChannelPermissionAsync(Id, user.Id).ConfigureAwait(false);
 
-            Overwrite value;
-            _overwrites.TryRemove(user.Id, out value);
+            for (int i = 0; i < _overwrites.Count; i++)
+            {
+                if (_overwrites[i].TargetId == user.Id)
+                {
+                    _overwrites.RemoveAt(i);
+                    return;
+                }
+            }
         }
         public async Task RemovePermissionOverwriteAsync(IRole role)
         {
             await Discord.ApiClient.DeleteChannelPermissionAsync(Id, role.Id).ConfigureAwait(false);
 
-            Overwrite value;
-            _overwrites.TryRemove(role.Id, out value);
+            for (int i = 0; i < _overwrites.Count; i++)
+            {
+                if (_overwrites[i].TargetId == role.Id)
+                {
+                    _overwrites.RemoveAt(i);
+                    return;
+                }
+            }
         }
         
         public override string ToString() => Name;
         private string DebuggerDisplay => $"{Name} ({Id})";
         
         IGuild IGuildChannel.Guild => Guild;
-        IReadOnlyCollection<Overwrite> IGuildChannel.PermissionOverwrites => _overwrites.ToReadOnlyCollection();
+        IReadOnlyCollection<Overwrite> IGuildChannel.PermissionOverwrites => _overwrites.AsReadOnly();
 
         async Task<IUser> IChannel.GetUserAsync(ulong id) => await GetUserAsync(id).ConfigureAwait(false);
         async Task<IReadOnlyCollection<IUser>> IChannel.GetUsersAsync() => await GetUsersAsync().ConfigureAwait(false);

src/Discord.Net/Entities/Users/GuildUser.cs

@@ -33,8 +33,9 @@ namespace Discord
         public bool IsBot => User.IsBot;
         public string Mention => User.Mention;
         public string Username => User.Username;
-        public virtual UserStatus Status => User.Status;
-        public virtual Game Game => User.Game;
+
+        public virtual UserStatus Status => UserStatus.Unknown;
+        public virtual Game Game => null;
 
         public DiscordClient Discord => Guild.Discord;
         public DateTimeOffset? JoinedAt => DateTimeUtils.FromTicks(_joinedAtTicks);

src/Discord.Net/Entities/Users/User.cs

@@ -1,7 +1,5 @@
-using Discord.API.Rest;
-using System;
+using System;
 using System.Diagnostics;
-using System.Threading.Tasks;
 using Model = Discord.API.User;
 
 namespace Discord

src/Discord.Net/Entities/WebSocket/CachedDMChannel.cs

@@ -9,16 +9,19 @@ namespace Discord
 {
     internal class CachedDMChannel : DMChannel, IDMChannel, ICachedChannel, ICachedMessageChannel
     {
-        private readonly MessageCache _messages;
+        private readonly MessageManager _messages;
 
         public new DiscordSocketClient Discord => base.Discord as DiscordSocketClient;
-        public new CachedPublicUser Recipient => base.Recipient as CachedPublicUser;
+        public new CachedDMUser Recipient => base.Recipient as CachedDMUser;
         public IReadOnlyCollection<ICachedUser> Members => ImmutableArray.Create<ICachedUser>(Discord.CurrentUser, Recipient);
 
-        public CachedDMChannel(DiscordSocketClient discord, CachedPublicUser recipient, Model model)
+        public CachedDMChannel(DiscordSocketClient discord, CachedDMUser recipient, Model model)
             : base(discord, recipient, model)
         {
-            _messages = new MessageCache(Discord, this);
+            if (Discord.MessageCacheSize > 0)
+                _messages = new MessageCache(Discord, this);
+            else
+                _messages = new MessageManager(Discord, this);
         }
 
         public override Task<IUser> GetUserAsync(ulong id) => Task.FromResult<IUser>(GetUser(id));

src/Discord.Net/Entities/WebSocket/CachedDMUser.cs

@@ -0,0 +1,38 @@
+using System;
+using PresenceModel = Discord.API.Presence;
+
+namespace Discord
+{
+    internal class CachedDMUser : ICachedUser
+    {
+        public CachedGlobalUser User { get; }
+
+        public Game Game { get; private set; }
+        public UserStatus Status { get; private set; }
+
+        public DiscordSocketClient Discord => User.Discord;
+        
+        public ulong Id => User.Id;
+        public string AvatarUrl => User.AvatarUrl;
+        public DateTimeOffset CreatedAt => User.CreatedAt;
+        public string Discriminator => User.Discriminator;
+        public bool IsAttached => User.IsAttached;
+        public bool IsBot => User.IsBot;
+        public string Mention => User.Mention;
+        public string Username => User.Username;
+
+        public CachedDMUser(CachedGlobalUser user)
+        {
+            User = user;
+        }
+
+        public void Update(PresenceModel model, UpdateSource source)
+        {
+            Status = model.Status;
+            Game = model.Game != null ? new Game(model.Game) : null;
+        }
+
+        public CachedDMUser Clone() => MemberwiseClone() as CachedDMUser;
+        ICachedUser ICachedUser.Clone() => Clone();
+    }
+}

src/Discord.Net/Entities/WebSocket/CachedGlobalUser.cs

@@ -0,0 +1,39 @@
+using System;
+using Model = Discord.API.User;
+
+namespace Discord
+{
+    internal class CachedGlobalUser : User, ICachedUser
+    {
+        private ushort _references;
+
+        public new DiscordSocketClient Discord { get { throw new NotSupportedException(); } }
+        public override UserStatus Status => UserStatus.Unknown;// _status;
+        public override Game Game => null; //_game;
+
+        public CachedGlobalUser(Model model) 
+            : base(model)
+        {
+        }
+
+        public void AddRef()
+        {
+            checked
+            {
+                lock (this)
+                    _references++;
+            }
+        }
+        public void RemoveRef(DiscordSocketClient discord)
+        {
+            lock (this)
+            {
+                if (--_references == 0)
+                    discord.RemoveUser(Id);
+            }
+        }
+
+        public CachedGlobalUser Clone() => MemberwiseClone() as CachedGlobalUser;
+        ICachedUser ICachedUser.Clone() => Clone();
+    }
+}

src/Discord.Net/Entities/WebSocket/CachedGuildUser.cs

@@ -10,7 +10,7 @@ namespace Discord
 
         public new DiscordSocketClient Discord => base.Discord as DiscordSocketClient;
         public new CachedGuild Guild => base.Guild as CachedGuild;
-        public new CachedPublicUser User => base.User as CachedPublicUser;
+        public new CachedGlobalUser User => base.User as CachedGlobalUser;
 
         public override Game Game => _game;
         public override UserStatus Status => _status;
@@ -21,11 +21,11 @@ namespace Discord
         public bool IsSuppressed => VoiceState?.IsSuppressed ?? false;
         public CachedVoiceChannel VoiceChannel => VoiceState?.VoiceChannel;
 
-        public CachedGuildUser(CachedGuild guild, CachedPublicUser user, Model model) 
+        public CachedGuildUser(CachedGuild guild, CachedGlobalUser user, Model model) 
             : base(guild, user, model)
         {
         }
-        public CachedGuildUser(CachedGuild guild, CachedPublicUser user, PresenceModel model)
+        public CachedGuildUser(CachedGuild guild, CachedGlobalUser user, PresenceModel model)
             : base(guild, user, model)
         {
         }

src/Discord.Net/Entities/WebSocket/CachedPublicUser.cs

@@ -1,75 +0,0 @@
-using ChannelModel = Discord.API.Channel;
-using Model = Discord.API.User;
-using PresenceModel = Discord.API.Presence;
-
-namespace Discord
-{
-    internal class CachedPublicUser : User, ICachedUser
-    {
-        //TODO: Fix removed game/status (add CachedDMUser?)
-        private int _references;
-        //private Game? _game;
-        //private UserStatus _status;
-
-        public CachedDMChannel DMChannel { get; private set; }
-
-        public new DiscordSocketClient Discord => base.Discord as DiscordSocketClient;
-        public override UserStatus Status => UserStatus.Unknown;// _status;
-        public override Game Game => null; //_game;
-
-        public CachedPublicUser(Model model) 
-            : base(model)
-        {
-        }
-
-        public CachedDMChannel AddDMChannel(DiscordSocketClient discord, ChannelModel model)
-        {
-            lock (this)
-            {
-                var channel = new CachedDMChannel(discord, this, model);
-                DMChannel = channel;
-                return channel;
-            }
-        }
-        public CachedDMChannel RemoveDMChannel(ulong id)
-        {
-            lock (this)
-            {
-                var channel = DMChannel;
-                if (channel.Id == id)
-                {
-                    DMChannel = null;
-                    return channel;
-                }
-                return null;
-            }
-        }
-
-        public void Update(PresenceModel model, UpdateSource source)
-        {
-            if (source == UpdateSource.Rest) return;
-
-            //var game = model.Game != null ? new Game(model.Game) : (Game)null;
-
-            //_status = model.Status;
-            //_game = game;
-        }
-
-        public void AddRef()
-        {
-            lock (this)
-                _references++;
-        }
-        public void RemoveRef(DiscordSocketClient discord)
-        {
-            lock (this)
-            {
-                if (--_references == 0 && DMChannel == null)
-                    discord.RemoveUser(Id);
-            }
-        }
-
-        public CachedPublicUser Clone() => MemberwiseClone() as CachedPublicUser;
-        ICachedUser ICachedUser.Clone() => Clone();
-    }
-}

src/Discord.Net/Entities/WebSocket/CachedTextChannel.cs

@@ -9,7 +9,7 @@ namespace Discord
 {
     internal class CachedTextChannel : TextChannel, ICachedGuildChannel, ICachedMessageChannel
     {
-        private readonly MessageCache _messages;
+        private readonly MessageManager _messages;
 
         public new DiscordSocketClient Discord => base.Discord as DiscordSocketClient;
         public new CachedGuild Guild => base.Guild as CachedGuild;
@@ -20,7 +20,10 @@ namespace Discord
         public CachedTextChannel(CachedGuild guild, Model model)
             : base(guild, model)
         {
-            _messages = new MessageCache(Discord, this);
+            if (Discord.MessageCacheSize > 0)
+                _messages = new MessageCache(Discord, this);
+            else
+                _messages = new MessageManager(Discord, this);
         }
 
         public override Task<IGuildUser> GetUserAsync(ulong id) => Task.FromResult<IGuildUser>(GetUser(id));

src/Discord.Net/Entities/WebSocket/MessageCache.cs

@@ -1,5 +1,4 @@
-using Discord.API.Rest;
-using Discord.Extensions;
+using Discord.Extensions;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -9,26 +8,23 @@ using System.Threading.Tasks;
 
 namespace Discord
 {
-    internal class MessageCache
+    internal class MessageCache : MessageManager
     {
-        private readonly DiscordSocketClient _discord;
-        private readonly ICachedMessageChannel _channel;
         private readonly ConcurrentDictionary<ulong, CachedMessage> _messages;
         private readonly ConcurrentQueue<ulong> _orderedMessages;
         private readonly int _size;
 
-        public IReadOnlyCollection<CachedMessage> Messages => _messages.ToReadOnlyCollection();
+        public override IReadOnlyCollection<CachedMessage> Messages => _messages.ToReadOnlyCollection();
 
         public MessageCache(DiscordSocketClient discord, ICachedMessageChannel channel)
+            : base(discord, channel)
         {
-            _discord = discord;
-            _channel = channel;
             _size = discord.MessageCacheSize;
             _messages = new ConcurrentDictionary<ulong, CachedMessage>(1, (int)(_size * 1.05));
             _orderedMessages = new ConcurrentQueue<ulong>();
         }
 
-        public void Add(CachedMessage message)
+        public override void Add(CachedMessage message)
         {
             if (_messages.TryAdd(message.Id, message))
             {
@@ -41,21 +37,21 @@ namespace Discord
             }
         }
 
-        public CachedMessage Remove(ulong id)
+        public override CachedMessage Remove(ulong id)
         {
             CachedMessage msg;
             _messages.TryRemove(id, out msg);
             return msg;
         }
 
-        public CachedMessage Get(ulong id)
+        public override CachedMessage Get(ulong id)
         {
             CachedMessage result;
             if (_messages.TryGetValue(id, out result))
                 return result;
             return null;
         }
-        public IImmutableList<CachedMessage> GetMany(ulong? fromMessageId, Direction dir, int limit = DiscordConfig.MaxMessagesPerBatch)
+        public override IImmutableList<CachedMessage> GetMany(ulong? fromMessageId, Direction dir, int limit = DiscordConfig.MaxMessagesPerBatch)
         {
             if (limit < 0) throw new ArgumentOutOfRangeException(nameof(limit));
             if (limit == 0) return ImmutableArray<CachedMessage>.Empty;
@@ -81,57 +77,12 @@ namespace Discord
                 .ToImmutableArray();
         }
 
-        public async Task<CachedMessage> DownloadAsync(ulong id)
+        public override async Task<CachedMessage> DownloadAsync(ulong id)
         {
             var msg = Get(id);
             if (msg != null)
                 return msg;
-            var model = await _discord.ApiClient.GetChannelMessageAsync(_channel.Id, id).ConfigureAwait(false);
-            if (model != null)
-                return new CachedMessage(_channel, new User(model.Author.Value), model);
-            return null;
-        }
-        public async Task<IReadOnlyCollection<CachedMessage>> DownloadAsync(ulong? fromId, Direction dir, int limit)
-        {
-            //TODO: Test heavily, especially the ordering of messages
-            if (limit < 0) throw new ArgumentOutOfRangeException(nameof(limit));
-            if (limit == 0) return ImmutableArray<CachedMessage>.Empty;
-
-            var cachedMessages = GetMany(fromId, dir, limit);
-            if (cachedMessages.Count == limit)
-                return cachedMessages;
-            else if (cachedMessages.Count > limit)
-                return cachedMessages.Skip(cachedMessages.Count - limit).ToImmutableArray();
-            else
-            {
-                Optional<ulong> relativeId;
-                if (cachedMessages.Count == 0)
-                    relativeId = fromId ?? new Optional<ulong>();
-                else
-                    relativeId = dir == Direction.Before ? cachedMessages[0].Id : cachedMessages[cachedMessages.Count - 1].Id;
-                var args = new GetChannelMessagesParams
-                {
-                    Limit = limit - cachedMessages.Count,
-                    RelativeDirection = dir,
-                    RelativeMessageId = relativeId
-                };
-                var downloadedMessages = await _discord.ApiClient.GetChannelMessagesAsync(_channel.Id, args).ConfigureAwait(false);
-
-                var guild = (_channel as ICachedGuildChannel).Guild;
-                return cachedMessages.Concat(downloadedMessages.Select(x =>
-                {
-                    IUser user = _channel.GetUser(x.Author.Value.Id, true);
-                    if (user == null)
-                    {
-                        var newUser = new User(x.Author.Value);
-                        if (guild != null)
-                            user = new GuildUser(guild, newUser);
-                        else
-                            user = newUser;
-                    }
-                    return new CachedMessage(_channel, user, x);
-                })).ToImmutableArray();
-            }
+            return await base.DownloadAsync(id).ConfigureAwait(false);
         }
     }
 }

src/Discord.Net/Entities/WebSocket/MessageManager.cs

@@ -0,0 +1,81 @@
+using Discord.API.Rest;
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Discord
+{
+    internal class MessageManager
+    {
+        private readonly DiscordSocketClient _discord;
+        private readonly ICachedMessageChannel _channel;
+
+        public virtual IReadOnlyCollection<CachedMessage> Messages 
+            => ImmutableArray.Create<CachedMessage>();
+
+        public MessageManager(DiscordSocketClient discord, ICachedMessageChannel channel)
+        {
+            _discord = discord;
+            _channel = channel;
+        }
+
+        public virtual void Add(CachedMessage message) { }
+        public virtual CachedMessage Remove(ulong id) => null;
+        public virtual CachedMessage Get(ulong id) => null;
+
+        public virtual IImmutableList<CachedMessage> GetMany(ulong? fromMessageId, Direction dir, int limit = DiscordConfig.MaxMessagesPerBatch)
+            => ImmutableArray.Create<CachedMessage>();
+
+        public virtual async Task<CachedMessage> DownloadAsync(ulong id)
+        {
+            var model = await _discord.ApiClient.GetChannelMessageAsync(_channel.Id, id).ConfigureAwait(false);
+            if (model != null)
+                return new CachedMessage(_channel, new User(model.Author.Value), model);
+            return null;
+        }
+        public async Task<IReadOnlyCollection<CachedMessage>> DownloadAsync(ulong? fromId, Direction dir, int limit)
+        {
+            //TODO: Test heavily, especially the ordering of messages
+            if (limit < 0) throw new ArgumentOutOfRangeException(nameof(limit));
+            if (limit == 0) return ImmutableArray<CachedMessage>.Empty;
+
+            var cachedMessages = GetMany(fromId, dir, limit);
+            if (cachedMessages.Count == limit)
+                return cachedMessages;
+            else if (cachedMessages.Count > limit)
+                return cachedMessages.Skip(cachedMessages.Count - limit).ToImmutableArray();
+            else
+            {
+                Optional<ulong> relativeId;
+                if (cachedMessages.Count == 0)
+                    relativeId = fromId ?? new Optional<ulong>();
+                else
+                    relativeId = dir == Direction.Before ? cachedMessages[0].Id : cachedMessages[cachedMessages.Count - 1].Id;
+                var args = new GetChannelMessagesParams
+                {
+                    Limit = limit - cachedMessages.Count,
+                    RelativeDirection = dir,
+                    RelativeMessageId = relativeId
+                };
+                var downloadedMessages = await _discord.ApiClient.GetChannelMessagesAsync(_channel.Id, args).ConfigureAwait(false);
+
+                var guild = (_channel as ICachedGuildChannel).Guild;
+                return cachedMessages.Concat(downloadedMessages.Select(x =>
+                {
+                    IUser user = _channel.GetUser(x.Author.Value.Id, true);
+                    if (user == null)
+                    {
+                        var newUser = new User(x.Author.Value);
+                        if (guild != null)
+                            user = new GuildUser(guild, newUser);
+                        else
+                            user = newUser;
+                    }
+                    return new CachedMessage(_channel, user, x);
+                })).ToImmutableArray();
+            }
+        }
+    }
+}