Several more database-y refactors

- DbConnectionFactory renamed to "Database", will now be the primary entry point for DB stuff
- Created IPKConnection interface mostly containing async extensions to IDbConnection, use this going forward
- Reworked the Connection/Command wrappers (that have performance/logging extensions)
- Probably more stuff that I forgot???

PluralKit.API/Controllers/SystemController.cs

@@ -40,10 +40,10 @@ namespace PluralKit.API
     public class SystemController : ControllerBase
     {
         private IDataStore _data;
-        private DbConnectionFactory _conn;
+        private Database _conn;
         private TokenAuthService _auth;
 
-        public SystemController(IDataStore data, DbConnectionFactory conn, TokenAuthService auth)
+        public SystemController(IDataStore data, Database conn, TokenAuthService auth)
         {
             _data = data;
             _conn = conn;

PluralKit.Bot/Commands/Autoproxy.cs

@@ -11,9 +11,9 @@ namespace PluralKit.Bot
 {
     public class Autoproxy
     {
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
 
-        public Autoproxy(DbConnectionFactory db)
+        public Autoproxy(Database db)
         {
             _db = db;
         }

PluralKit.Bot/Commands/MemberAvatar.cs

@@ -14,9 +14,9 @@ namespace PluralKit.Bot
 {
     public class MemberAvatar
     {
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
 
-        public MemberAvatar(DbConnectionFactory db)
+        public MemberAvatar(Database db)
         {
             _db = db;
         }

PluralKit.Bot/Commands/MemberEdit.cs

@@ -12,9 +12,9 @@ namespace PluralKit.Bot
     public class MemberEdit
     {
         private readonly IDataStore _data;
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
 
-        public MemberEdit(IDataStore data, DbConnectionFactory db)
+        public MemberEdit(IDataStore data, Database db)
         {
             _data = data;
             _db = db;

PluralKit.Bot/Commands/ServerConfig.cs

@@ -13,9 +13,9 @@ namespace PluralKit.Bot
 {
     public class ServerConfig
     {
-        private DbConnectionFactory _db;
+        private Database _db;
         private LoggerCleanService _cleanService;
-        public ServerConfig(LoggerCleanService cleanService, DbConnectionFactory db)
+        public ServerConfig(LoggerCleanService cleanService, Database db)
         {
             _cleanService = cleanService;
             _db = db;

PluralKit.Bot/Commands/SystemEdit.cs

@@ -18,10 +18,10 @@ namespace PluralKit.Bot
     public class SystemEdit
     {
         private IDataStore _data;
-        private DbConnectionFactory _db;
+        private Database _db;
         private EmbedService _embeds;
 
-        public SystemEdit(IDataStore data, EmbedService embeds, DbConnectionFactory db)
+        public SystemEdit(IDataStore data, EmbedService embeds, Database db)
         {
             _data = data;
             _embeds = embeds;

PluralKit.Bot/Commands/SystemList.cs

@@ -16,10 +16,10 @@ namespace PluralKit.Bot
     public class SystemList
     {
         private readonly IClock _clock;
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
         private readonly ILogger _logger;
         
-        public SystemList(DbConnectionFactory db, ILogger logger, IClock clock)
+        public SystemList(Database db, ILogger logger, IClock clock)
         {
             _db = db;
             _logger = logger;

PluralKit.Bot/Handlers/MessageCreated.cs

@@ -22,12 +22,12 @@ namespace PluralKit.Bot
         private readonly IMetrics _metrics;
         private readonly ProxyService _proxy;
         private readonly ILifetimeScope _services;
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
         private readonly IDataStore _data;
 
         public MessageCreated(LastMessageCacheService lastMessageCache, LoggerCleanService loggerClean,
                               IMetrics metrics, ProxyService proxy, DiscordShardedClient client,
-                              CommandTree tree, ILifetimeScope services, DbConnectionFactory db, IDataStore data)
+                              CommandTree tree, ILifetimeScope services, Database db, IDataStore data)
         {
             _lastMessageCache = lastMessageCache;
             _loggerClean = loggerClean;

PluralKit.Bot/Handlers/MessageEdited.cs

@@ -11,9 +11,9 @@ namespace PluralKit.Bot
     {
         private readonly LastMessageCacheService _lastMessageCache;
         private readonly ProxyService _proxy;
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
 
-        public MessageEdited(LastMessageCacheService lastMessageCache, ProxyService proxy, DbConnectionFactory db)
+        public MessageEdited(LastMessageCacheService lastMessageCache, ProxyService proxy, Database db)
         {
             _lastMessageCache = lastMessageCache;
             _proxy = proxy;

PluralKit.Bot/Proxy/ProxyService.cs

@@ -21,14 +21,14 @@ namespace PluralKit.Bot
         public static readonly TimeSpan MessageDeletionDelay = TimeSpan.FromMilliseconds(1000);
 
         private readonly LogChannelService _logChannel;
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
         private readonly IDataStore _data;
         private readonly ILogger _logger;
         private readonly WebhookExecutorService _webhookExecutor;
         private readonly ProxyMatcher _matcher;
 
         public ProxyService(LogChannelService logChannel, IDataStore data, ILogger logger,
-                            WebhookExecutorService webhookExecutor, DbConnectionFactory db, ProxyMatcher matcher)
+                            WebhookExecutorService webhookExecutor, Database db, ProxyMatcher matcher)
         {
             _logChannel = logChannel;
             _data = data;
@@ -43,7 +43,8 @@ namespace PluralKit.Bot
             if (!ShouldProxy(message, ctx)) return false;
 
             // Fetch members and try to match to a specific member
-            var members = (await _db.Execute(c => c.QueryProxyMembers(message.Author.Id, message.Channel.GuildId))).ToList();
+            await using var conn = await _db.Obtain();
+            var members = (await conn.QueryProxyMembers(message.Author.Id, message.Channel.GuildId)).ToList();
             if (!_matcher.TryMatch(ctx, members, out var match, message.Content, message.Attachments.Count > 0,
                 allowAutoproxy)) return false;
 
@@ -52,7 +53,7 @@ namespace PluralKit.Bot
             if (!CheckProxyNameBoundsOrError(match.Member.ProxyName(ctx))) return false;
 
             // Everything's in order, we can execute the proxy!
-            await ExecuteProxy(message, ctx, match);
+            await ExecuteProxy(conn, message, ctx, match);
             return true;
         }
 
@@ -78,29 +79,39 @@ namespace PluralKit.Bot
             return true;
         }
 
-        private async Task ExecuteProxy(DiscordMessage trigger, MessageContext ctx, ProxyMatch match)
+        private async Task ExecuteProxy(IPKConnection conn, DiscordMessage trigger, MessageContext ctx,
+                                        ProxyMatch match)
         {
             // Send the webhook
             var id = await _webhookExecutor.ExecuteWebhook(trigger.Channel, match.Member.ProxyName(ctx),
                 match.Member.ProxyAvatar(ctx),
                 match.Content, trigger.Attachments);
 
-            // Handle post-proxy actions
-            await _data.AddMessage(trigger.Author.Id, trigger.Channel.GuildId, trigger.Channel.Id, id, trigger.Id,
-                match.Member.Id);
-            await _logChannel.LogMessage(ctx, match, trigger, id);
-
-            // Wait a second or so before deleting the original message
-            await Task.Delay(MessageDeletionDelay);
-            try
+                        
+            Task SaveMessage() => _data.AddMessage(conn, trigger.Author.Id, trigger.Channel.GuildId, trigger.Channel.Id, id, trigger.Id, match.Member.Id);
+            Task LogMessage() => _logChannel.LogMessage(ctx, match, trigger, id).AsTask();
+            async Task DeleteMessage()
             {
-                await trigger.DeleteAsync();
-            }
-            catch (NotFoundException)
-            {
-                // If it's already deleted, we just log and swallow the exception
-                _logger.Warning("Attempted to delete already deleted proxy trigger message {Message}", trigger.Id);
+                // Wait a second or so before deleting the original message
+                await Task.Delay(MessageDeletionDelay);
+                try
+                {
+                    await trigger.DeleteAsync();
+                }
+                catch (NotFoundException)
+                {
+                    // If it's already deleted, we just log and swallow the exception
+                    _logger.Warning("Attempted to delete already deleted proxy trigger message {Message}", trigger.Id);
+                }
             }
+            
+            // Run post-proxy actions (simultaneously; order doesn't matter)
+            // Note that only AddMessage is using our passed-in connection, careful not to pass it elsewhere and run into conflicts
+            await Task.WhenAll(
+                DeleteMessage(),
+                SaveMessage(),
+                LogMessage()
+            );
         }
         
         private async Task<bool> CheckBotPermissionsOrError(DiscordChannel channel)

PluralKit.Bot/Services/EmbedService.cs

@@ -16,10 +16,10 @@ namespace PluralKit.Bot {
     public class EmbedService
     {
         private IDataStore _data;
-        private DbConnectionFactory _db;
+        private Database _db;
         private DiscordShardedClient _client;
 
-        public EmbedService(DiscordShardedClient client, IDataStore data, DbConnectionFactory db)
+        public EmbedService(DiscordShardedClient client, IDataStore data, Database db)
         {
             _client = client;
             _data = data;

PluralKit.Bot/Services/LogChannelService.cs

@@ -14,12 +14,12 @@ using Serilog;
 namespace PluralKit.Bot {
     public class LogChannelService {
         private readonly EmbedService _embed;
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
         private readonly IDataStore _data;
         private readonly ILogger _logger;
         private readonly DiscordRestClient _rest;
 
-        public LogChannelService(EmbedService embed, ILogger logger, DiscordRestClient rest, DbConnectionFactory db, IDataStore data)
+        public LogChannelService(EmbedService embed, ILogger logger, DiscordRestClient rest, Database db, IDataStore data)
         {
             _embed = embed;
             _rest = rest;

PluralKit.Bot/Services/LoggerCleanService.cs

@@ -53,10 +53,10 @@ namespace PluralKit.Bot
             .Where(b => b.WebhookName != null)
             .ToDictionary(b => b.WebhookName);
 
-        private DbConnectionFactory _db;
+        private Database _db;
         private DiscordShardedClient _client;
         
-        public LoggerCleanService(DbConnectionFactory db, DiscordShardedClient client)
+        public LoggerCleanService(Database db, DiscordShardedClient client)
         {
             _db = db;
             _client = client;

PluralKit.Core/CoreConfig.cs

@@ -1,3 +1,5 @@
+using Serilog.Events;
+
 namespace PluralKit.Core
 {
     public class CoreConfig
@@ -7,5 +9,8 @@ namespace PluralKit.Core
         public string InfluxUrl { get; set; }
         public string InfluxDb { get; set; }
         public string LogDir { get; set; }
+
+        public LogEventLevel ConsoleLogLevel { get; set; } = LogEventLevel.Verbose;
+        public LogEventLevel FileLogLevel { get; set; } = LogEventLevel.Information;
     }
 }

PluralKit.Core/Database/Database.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Threading.Tasks;
+
+using App.Metrics;
+
+using Npgsql;
+
+using Serilog;
+
+namespace PluralKit.Core
+{
+    public class Database
+    {
+        private readonly CoreConfig _config;
+        private readonly ILogger _logger;
+        private readonly IMetrics _metrics;
+        private readonly DbConnectionCountHolder _countHolder;
+
+        public Database(CoreConfig config, DbConnectionCountHolder countHolder, ILogger logger,
+                        IMetrics metrics)
+        {
+            _config = config;
+            _countHolder = countHolder;
+            _metrics = metrics;
+            _logger = logger;
+        }
+
+        public async Task<IPKConnection> Obtain()
+        {
+            // Mark the request (for a handle, I guess) in the metrics
+            _metrics.Measure.Meter.Mark(CoreMetrics.DatabaseRequests);
+            
+            // Create a connection and open it
+            // We wrap it in PKConnection for tracing purposes
+            var conn = new PKConnection(new NpgsqlConnection(_config.Database), _countHolder, _logger, _metrics);
+            await conn.OpenAsync();
+            return conn;
+        }
+        
+        public async Task Execute(Func<IPKConnection, Task> func)
+        {
+            await using var conn = await Obtain();
+            await func(conn);
+        }
+        
+        public async Task<T> Execute<T>(Func<IPKConnection, Task<T>> func)
+        {
+            await using var conn = await Obtain();
+            return await func(conn);
+        }
+    }
+}

PluralKit.Core/Database/Functions/DatabaseFunctionsExt.cs

@@ -8,14 +8,14 @@ namespace PluralKit.Core
 {
     public static class DatabaseFunctionsExt
     {
-        public static Task<MessageContext> QueryMessageContext(this IDbConnection conn, ulong account, ulong guild, ulong channel)
+        public static Task<MessageContext> QueryMessageContext(this IPKConnection conn, ulong account, ulong guild, ulong channel)
         {
             return conn.QueryFirstAsync<MessageContext>("message_context", 
                 new { account_id = account, guild_id = guild, channel_id = channel }, 
                 commandType: CommandType.StoredProcedure);
         }  
         
-        public static Task<IEnumerable<ProxyMember>> QueryProxyMembers(this IDbConnection conn, ulong account, ulong guild)
+        public static Task<IEnumerable<ProxyMember>> QueryProxyMembers(this IPKConnection conn, ulong account, ulong guild)
         {
             return conn.QueryAsync<ProxyMember>("proxy_members", 
                 new { account_id = account, guild_id = guild }, 

PluralKit.Core/Database/Schemas.cs

@@ -16,10 +16,10 @@ namespace PluralKit.Core
         private const string RootPath = "PluralKit.Core.Database"; // "resource path" root for SQL files
         private const int TargetSchemaVersion = 7;
 
-        private DbConnectionFactory _conn;
+        private Database _conn;
         private ILogger _logger;
 
-        public Schemas(DbConnectionFactory conn, ILogger logger)
+        public Schemas(Database conn, ILogger logger)
         {
             _conn = conn;
             _logger = logger.ForContext<Schemas>();
@@ -36,7 +36,7 @@ namespace PluralKit.Core
         {
             // Run everything in a transaction
             await using var conn = await _conn.Obtain();
-            using var tx = conn.BeginTransaction();
+            await using var tx = await conn.BeginTransactionAsync();
             
             // Before applying migrations, clean out views/functions to prevent type errors
             await ExecuteSqlFile($"{RootPath}.clean.sql", conn, tx);
@@ -49,10 +49,10 @@ namespace PluralKit.Core
             await ExecuteSqlFile($"{RootPath}.Functions.functions.sql", conn, tx);
 
             // Finally, commit tx
-            tx.Commit();
+            await tx.CommitAsync();
         }
 
-        private async Task ApplyMigrations(IAsyncDbConnection conn, IDbTransaction tx)
+        private async Task ApplyMigrations(IPKConnection conn, IDbTransaction tx)
         {
             var currentVersion = await GetCurrentDatabaseVersion(conn);
             _logger.Information("Current schema version: {CurrentVersion}", currentVersion);
@@ -63,7 +63,7 @@ namespace PluralKit.Core
             }
         }
 
-        private async Task ExecuteSqlFile(string resourceName, IDbConnection conn, IDbTransaction tx = null)
+        private async Task ExecuteSqlFile(string resourceName, IPKConnection conn, IDbTransaction tx = null)
         {
             await using var stream = typeof(Schemas).Assembly.GetManifestResourceStream(resourceName);
             if (stream == null) throw new ArgumentException($"Invalid resource name  '{resourceName}'");
@@ -76,10 +76,10 @@ namespace PluralKit.Core
             // If the above creates new enum/composite types, we must tell Npgsql to reload the internal type caches
             // This will propagate to every other connection as well, since it marks the global type mapper collection dirty.
             // TODO: find a way to get around the cast to our internal tracker wrapper... this could break if that ever changes
-            ((PerformanceTrackingConnection) conn)._impl.ReloadTypes();
+            conn.ReloadTypes();
         }
 
-        private async Task<int> GetCurrentDatabaseVersion(IDbConnection conn)
+        private async Task<int> GetCurrentDatabaseVersion(IPKConnection conn)
         {
             // First, check if the "info" table exists (it may not, if this is a *really* old database)
             var hasInfoTable =

PluralKit.Core/Database/Wrappers/IPKCommand.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Data;
+using System.Data.Common;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace PluralKit.Core
+{
+    public interface IPKCommand: IDbCommand, IAsyncDisposable
+    {
+        public Task PrepareAsync(CancellationToken ct = default);
+        public Task<int> ExecuteNonQueryAsync(CancellationToken ct = default);
+        public Task<object> ExecuteScalarAsync(CancellationToken ct = default);
+        public Task<DbDataReader> ExecuteReaderAsync(CancellationToken ct = default);
+        public Task<DbDataReader> ExecuteReaderAsync(CommandBehavior behavior, CancellationToken ct = default);
+    }
+}

PluralKit.Core/Database/Wrappers/IPKConnection.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Data;
+using System.Data.Common;
+using System.Threading;
+using System.Threading.Tasks;
+
+using Npgsql;
+
+namespace PluralKit.Core
+{
+    public interface IPKConnection: IDbConnection, IAsyncDisposable
+    {
+        public Guid ConnectionId { get; }
+        
+        public Task OpenAsync(CancellationToken cancellationToken = default);
+        public Task CloseAsync();
+
+        public Task ChangeDatabaseAsync(string databaseName, CancellationToken ct = default);
+        
+        public ValueTask<DbTransaction> BeginTransactionAsync(CancellationToken ct = default) => BeginTransactionAsync(IsolationLevel.Unspecified, ct);
+        public ValueTask<DbTransaction> BeginTransactionAsync(IsolationLevel level, CancellationToken ct = default);
+        
+        public NpgsqlBinaryImporter BeginBinaryImport(string copyFromCommand);
+        public NpgsqlBinaryExporter BeginBinaryExport(string copyToCommand);
+
+        public void ReloadTypes();
+
+        [Obsolete] new void Open();
+        [Obsolete] new void Close();
+
+        [Obsolete] new IDbTransaction BeginTransaction();
+        [Obsolete] new IDbTransaction BeginTransaction(IsolationLevel il);
+    }
+}

PluralKit.Core/Database/Wrappers/PKCommand.cs

@@ -0,0 +1,117 @@
+#nullable enable
+using System;
+using System.Data;
+using System.Data.Common;
+using System.Threading;
+using System.Threading.Tasks;
+
+using App.Metrics;
+
+using NodaTime;
+
+using Npgsql;
+
+using Serilog;
+
+namespace PluralKit.Core
+{
+    public class PKCommand: DbCommand, IPKCommand
+    {
+        private readonly NpgsqlCommand _inner;
+        private readonly PKConnection _ourConnection;
+        private readonly ILogger _logger;
+        private readonly IMetrics _metrics;
+        
+        public PKCommand(NpgsqlCommand inner, PKConnection ourConnection, ILogger logger, IMetrics metrics)
+        {
+            _inner = inner;
+            _ourConnection = ourConnection;
+            _logger = logger.ForContext<PKCommand>();
+            _metrics = metrics;
+        }
+
+        public override int ExecuteNonQuery() => throw SyncError(nameof(ExecuteNonQuery));
+        public override object ExecuteScalar() => throw SyncError(nameof(ExecuteScalar));
+        protected override DbDataReader ExecuteDbDataReader(CommandBehavior behavior) => throw SyncError(nameof(ExecuteDbDataReader));
+
+        public override Task<int> ExecuteNonQueryAsync(CancellationToken ct) => LogQuery(_inner.ExecuteNonQueryAsync(ct));
+        public override Task<object> ExecuteScalarAsync(CancellationToken ct) => LogQuery(_inner.ExecuteScalarAsync(ct));
+        protected override async Task<DbDataReader> ExecuteDbDataReaderAsync(CommandBehavior behavior, CancellationToken ct) => await LogQuery(_inner.ExecuteReaderAsync(behavior, ct));
+
+        public override void Prepare() => _inner.Prepare();
+        public override void Cancel() => _inner.Cancel();
+        protected override DbParameter CreateDbParameter() => _inner.CreateParameter();
+
+        public override string CommandText
+        {
+            get => _inner.CommandText;
+            set => _inner.CommandText = value;
+        }
+
+        public override int CommandTimeout
+        {
+            get => _inner.CommandTimeout;
+            set => _inner.CommandTimeout = value;
+        }
+
+        public override CommandType CommandType
+        {
+            get => _inner.CommandType;
+            set => _inner.CommandType = value;
+        }
+
+        public override UpdateRowSource UpdatedRowSource
+        {
+            get => _inner.UpdatedRowSource;
+            set => _inner.UpdatedRowSource = value;
+        }
+
+        protected override DbParameterCollection DbParameterCollection => _inner.Parameters;
+        protected override DbTransaction? DbTransaction
+        {
+            get => _inner.Transaction;
+            set => _inner.Transaction = (NpgsqlTransaction?) value;
+        }
+
+        public override bool DesignTimeVisible
+        {
+            get => _inner.DesignTimeVisible;
+            set => _inner.DesignTimeVisible = value;
+        }
+
+        protected override DbConnection? DbConnection
+        {
+            get => _inner.Connection;
+            set =>
+                _inner.Connection = value switch
+                {
+                    NpgsqlConnection npg => npg,
+                    PKConnection pk => pk.Inner,
+                    _ => throw new ArgumentException($"Can't convert input type {value?.GetType()} to NpgsqlConnection")
+                };
+        }
+        
+        private async Task<T> LogQuery<T>(Task<T> task)
+        {
+            var start = SystemClock.Instance.GetCurrentInstant();
+            try
+            {
+                return await task;
+            }
+            finally
+            {
+                var end = SystemClock.Instance.GetCurrentInstant();
+                var elapsed = end - start;
+                
+                _logger.Verbose("Executed query {Query} in {ElapsedTime} on connection {ConnectionId}", CommandText, elapsed, _ourConnection.ConnectionId);
+                
+                // One "BCL compatible tick" is 100 nanoseconds
+                var micros = elapsed.BclCompatibleTicks / 10;
+                _metrics.Provider.Timer.Instance(CoreMetrics.DatabaseQuery, new MetricTags("query", CommandText))
+                    .Record(micros, TimeUnit.Microseconds, CommandText);
+            }
+        }
+        
+        private static Exception SyncError(string caller) => throw new Exception($"Executed synchronous IPKCommand function {caller}!");
+    }
+}

PluralKit.Core/Database/Wrappers/PKConnection.cs

@@ -0,0 +1,107 @@
+#nullable enable
+using System;
+using System.Data;
+using System.Data.Common;
+using System.Threading;
+using System.Threading.Tasks;
+
+using App.Metrics;
+
+using NodaTime;
+
+using Npgsql;
+
+using Serilog;
+
+namespace PluralKit.Core
+{
+    public class PKConnection: DbConnection, IPKConnection
+    {
+        public NpgsqlConnection Inner { get; }
+        public Guid ConnectionId { get; }
+
+        private readonly DbConnectionCountHolder _countHolder;
+        private readonly ILogger _logger;
+        private readonly IMetrics _metrics;
+
+        private bool _hasOpened;
+        private bool _hasClosed;
+        private Instant _openTime;
+
+        public PKConnection(NpgsqlConnection inner, DbConnectionCountHolder countHolder, ILogger logger, IMetrics metrics)
+        {
+            Inner = inner;
+            ConnectionId = Guid.NewGuid();
+            _countHolder = countHolder;
+            _logger = logger.ForContext<PKConnection>();
+            _metrics = metrics;
+        }
+        
+        public override Task OpenAsync(CancellationToken ct)
+        {
+            if (_hasOpened) return Inner.OpenAsync(ct);
+            _countHolder.Increment();
+            _hasOpened = true;
+            _openTime = SystemClock.Instance.GetCurrentInstant();
+            _logger.Verbose("Opened database connection {ConnectionId}, new connection count {ConnectionCount}", ConnectionId, _countHolder.ConnectionCount);       
+            return Inner.OpenAsync(ct);
+        }
+
+        public override Task CloseAsync() => Inner.CloseAsync();
+
+        protected override DbCommand CreateDbCommand() => new PKCommand(Inner.CreateCommand(), this, _logger, _metrics);
+        
+        public void ReloadTypes() => Inner.ReloadTypes();
+        
+        public NpgsqlBinaryImporter BeginBinaryImport(string copyFromCommand) => Inner.BeginBinaryImport(copyFromCommand);
+        public NpgsqlBinaryExporter BeginBinaryExport(string copyToCommand) => Inner.BeginBinaryExport(copyToCommand);
+        
+        public override void ChangeDatabase(string databaseName) => Inner.ChangeDatabase(databaseName);
+        public override Task ChangeDatabaseAsync(string databaseName, CancellationToken ct = default) => Inner.ChangeDatabaseAsync(databaseName, ct);
+        protected override DbTransaction BeginDbTransaction(IsolationLevel isolationLevel) => throw SyncError(nameof(BeginDbTransaction));
+        protected override async ValueTask<DbTransaction> BeginDbTransactionAsync(IsolationLevel level, CancellationToken ct) => await Inner.BeginTransactionAsync(level, ct);
+
+        public override void Open() => throw SyncError(nameof(Open));
+        public override void Close() => throw SyncError(nameof(Close));
+
+        IDbTransaction IPKConnection.BeginTransaction() => throw SyncError(nameof(BeginTransaction));
+        IDbTransaction IPKConnection.BeginTransaction(IsolationLevel level) => throw SyncError(nameof(BeginTransaction));
+
+        public override string ConnectionString
+        {
+            get => Inner.ConnectionString;
+            set => Inner.ConnectionString = value;
+        }
+
+        public override string? Database => Inner.Database;
+        public override ConnectionState State => Inner.State;
+        public override string DataSource => Inner.DataSource;
+        public override string ServerVersion => Inner.ServerVersion;
+        
+        protected override void Dispose(bool disposing)
+        { 
+            Inner.Dispose();
+            if (_hasClosed) return;
+            
+            LogClose();
+        }
+
+        public override ValueTask DisposeAsync()
+        {
+            if (_hasClosed) return Inner.DisposeAsync();
+            LogClose();
+            return Inner.DisposeAsync();
+        }
+        
+        private void LogClose()
+        {
+            _countHolder.Decrement();
+            _hasClosed = true;
+            
+            var duration = SystemClock.Instance.GetCurrentInstant() - _openTime;
+            _logger.Verbose("Closed database connection {ConnectionId} (open for {ConnectionDuration}), new connection count {ConnectionCount}", ConnectionId, duration, _countHolder.ConnectionCount);
+        }
+
+        private static Exception SyncError(string caller) => throw new Exception($"Executed synchronous IPKConnection function {caller}!");
+    }
+}

PluralKit.Core/Models/ModelQueryExt.cs

@@ -1,5 +1,4 @@
 #nullable enable
-using System;
 using System.Data;
 using System.Threading.Tasks;
 
@@ -9,19 +8,19 @@ namespace PluralKit.Core
 {
     public static class ModelQueryExt
     {
-        public static Task<PKMember?> QueryMember(this IDbConnection conn, int id) =>
+        public static Task<PKMember?> QueryMember(this IPKConnection conn, int id) =>
             conn.QueryFirstOrDefaultAsync<PKMember?>("select * from members where id = @id", new {id});
         
-        public static Task<GuildConfig> QueryOrInsertGuildConfig(this IDbConnection conn, ulong guild) =>
+        public static Task<GuildConfig> QueryOrInsertGuildConfig(this IPKConnection conn, ulong guild) =>
             conn.QueryFirstAsync<GuildConfig>("insert into servers (id) values (@Guild) on conflict do nothing returning *", new {Guild = guild});
 
-        public static Task<SystemGuildSettings> QueryOrInsertSystemGuildConfig(this IDbConnection conn, ulong guild, int system) =>
+        public static Task<SystemGuildSettings> QueryOrInsertSystemGuildConfig(this IPKConnection conn, ulong guild, int system) =>
             conn.QueryFirstAsync<SystemGuildSettings>(
                 "insert into member_guild (guild, member) values (@guild, @member) on conflict (guild, member) do update set guild = @guild, member = @member returning *", 
                 new {guild, system});
 
         public static Task<MemberGuildSettings> QueryOrInsertMemberGuildConfig(
-            this IDbConnection conn, ulong guild, int member) =>
+            this IPKConnection conn, ulong guild, int member) =>
             conn.QueryFirstAsync<MemberGuildSettings>(
                 "insert into member_guild (guild, member) values (@guild, @member) on conflict (guild, member) do update set guild = @guild, member = @member returning *",
                 new {guild, member});

PluralKit.Core/Modules.cs

@@ -23,7 +23,7 @@ namespace PluralKit.Core
         protected override void Load(ContainerBuilder builder)
         {
             builder.RegisterType<DbConnectionCountHolder>().SingleInstance();
-            builder.RegisterType<DbConnectionFactory>().AsSelf().SingleInstance();
+            builder.RegisterType<Database>().AsSelf().SingleInstance();
             builder.RegisterType<PostgresDataStore>().AsSelf().As<IDataStore>();
             builder.RegisterType<Schemas>().AsSelf();
             
@@ -99,7 +99,7 @@ namespace PluralKit.Core
 
             return new LoggerConfiguration()
                 .ConfigureForNodaTime(DateTimeZoneProviders.Tzdb)
-                .MinimumLevel.Debug()
+                .MinimumLevel.Is(config.ConsoleLogLevel)
                 .WriteTo.Async(a =>
                 {
                     // Both the same output, except one is raw compact JSON and one is plain text.
@@ -110,7 +110,7 @@ namespace PluralKit.Core
                         outputTemplate: outputTemplate,
                         rollingInterval: RollingInterval.Day,
                         flushToDiskInterval: TimeSpan.FromMilliseconds(50),
-                        restrictedToMinimumLevel: LogEventLevel.Information,
+                        restrictedToMinimumLevel: config.FileLogLevel,
                         formatProvider: new UTCTimestampFormatProvider(),
                         buffered: true);
                     
@@ -119,7 +119,7 @@ namespace PluralKit.Core
                         (config.LogDir ?? "logs") + $"/pluralkit.{_component}.json",
                         rollingInterval: RollingInterval.Day,
                         flushToDiskInterval: TimeSpan.FromMilliseconds(50),
-                        restrictedToMinimumLevel: LogEventLevel.Information,
+                        restrictedToMinimumLevel: config.FileLogLevel,
                         buffered: true);
                 })
                 // TODO: render as UTC in the console, too? or just in log files

PluralKit.Core/Services/DataFileService.cs

@@ -15,10 +15,10 @@ namespace PluralKit.Core
     public class DataFileService
     {
         private IDataStore _data;
-        private DbConnectionFactory _db;
+        private Database _db;
         private ILogger _logger;
 
-        public DataFileService(ILogger logger, IDataStore data, DbConnectionFactory db)
+        public DataFileService(ILogger logger, IDataStore data, Database db)
         {
             _data = data;
             _db = db;
@@ -127,8 +127,8 @@ namespace PluralKit.Core
             await _data.SaveSystem(system);
             
             // -- Member/switch import --
-            await using var conn = (PerformanceTrackingConnection) await _db.Obtain();
-            await using (var imp = await BulkImporter.Begin(system, conn._impl))
+            await using var conn = await _db.Obtain();
+            await using (var imp = await BulkImporter.Begin(system, conn))
             {
                 // Tally up the members that didn't exist before, and check member count on import
                 // If creating the unmatched members would put us over the member limit, abort before creating any members

PluralKit.Core/Services/IDataStore.cs

@@ -201,7 +201,7 @@ namespace PluralKit.Core {
         /// <param name="triggerMessageId">The ID of the original trigger message containing the proxy tags.</param>
         /// <param name="proxiedMemberId">The member (and by extension system) that was proxied.</param>
         /// <returns></returns>
-        Task AddMessage(ulong senderAccount, ulong guildId, ulong channelId, ulong postedMessageId, ulong triggerMessageId, int proxiedMemberId);
+        Task AddMessage(IPKConnection conn, ulong senderAccount, ulong guildId, ulong channelId, ulong postedMessageId, ulong triggerMessageId, int proxiedMemberId);
         
         /// <summary>
         /// Deletes a message from the data store.

PluralKit.Core/Services/PostgresDataStore.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 
@@ -10,10 +10,10 @@ using Serilog;
 
 namespace PluralKit.Core {
     public class PostgresDataStore: IDataStore {
-        private DbConnectionFactory _conn;
+        private Database _conn;
         private ILogger _logger;
 
-        public PostgresDataStore(DbConnectionFactory conn, ILogger logger)
+        public PostgresDataStore(Database conn, ILogger logger)
         {
             _conn = conn;
             _logger = logger;
@@ -182,17 +182,17 @@ namespace PluralKit.Core {
             using (var conn = await _conn.Obtain())
                 return await conn.ExecuteScalarAsync<ulong>("select count(id) from members");
         }
-        public async Task AddMessage(ulong senderId, ulong guildId, ulong channelId, ulong postedMessageId, ulong triggerMessageId, int proxiedMemberId) {
-            using (var conn = await _conn.Obtain())
-                // "on conflict do nothing" in the (pretty rare) case of duplicate events coming in from Discord, which would lead to a DB error before
-                await conn.ExecuteAsync("insert into messages(mid, guild, channel, member, sender, original_mid) values(@MessageId, @GuildId, @ChannelId, @MemberId, @SenderId, @OriginalMid) on conflict do nothing", new {
-                    MessageId = postedMessageId,
-                    GuildId = guildId,
-                    ChannelId = channelId,
-                    MemberId = proxiedMemberId,
-                    SenderId = senderId,
-                    OriginalMid = triggerMessageId
-                });
+        
+        public async Task AddMessage(IPKConnection conn, ulong senderId, ulong guildId, ulong channelId, ulong postedMessageId, ulong triggerMessageId, int proxiedMemberId) {
+            // "on conflict do nothing" in the (pretty rare) case of duplicate events coming in from Discord, which would lead to a DB error before
+            await conn.ExecuteAsync("insert into messages(mid, guild, channel, member, sender, original_mid) values(@MessageId, @GuildId, @ChannelId, @MemberId, @SenderId, @OriginalMid) on conflict do nothing", new {
+                MessageId = postedMessageId,
+                GuildId = guildId,
+                ChannelId = channelId,
+                MemberId = proxiedMemberId,
+                SenderId = senderId,
+                OriginalMid = triggerMessageId
+            });
 
             _logger.Debug("Stored message {Message} in channel {Channel}", postedMessageId, channelId);
         }
@@ -235,27 +235,26 @@ namespace PluralKit.Core {
         public async Task AddSwitch(PKSystem system, IEnumerable<PKMember> members)
         {
             // Use a transaction here since we're doing multiple executed commands in one
-            using (var conn = await _conn.Obtain())
-            using (var tx = conn.BeginTransaction())
+            await using var conn = await _conn.Obtain();
+            using var tx = await conn.BeginTransactionAsync();
+            
+            // First, we insert the switch itself
+            var sw = await conn.QuerySingleAsync<PKSwitch>("insert into switches(system) values (@System) returning *",
+                new {System = system.Id});
+
+            // Then we insert each member in the switch in the switch_members table
+            // TODO: can we parallelize this or send it in bulk somehow?
+            foreach (var member in members)
             {
-                // First, we insert the switch itself
-                var sw = await conn.QuerySingleAsync<PKSwitch>("insert into switches(system) values (@System) returning *",
-                    new {System = system.Id});
-
-                // Then we insert each member in the switch in the switch_members table
-                // TODO: can we parallelize this or send it in bulk somehow?
-                foreach (var member in members)
-                {
-                    await conn.ExecuteAsync(
-                        "insert into switch_members(switch, member) values(@Switch, @Member)",
-                        new {Switch = sw.Id, Member = member.Id});
-                }
-
-                // Finally we commit the tx, since the using block will otherwise rollback it
-                tx.Commit();
-
-                _logger.Information("Registered switch {Switch} in system {System} with members {@Members}", sw.Id, system.Id, members.Select(m => m.Id));
+                await conn.ExecuteAsync(
+                    "insert into switch_members(switch, member) values(@Switch, @Member)",
+                    new {Switch = sw.Id, Member = member.Id});
             }
+
+            // Finally we commit the tx, since the using block will otherwise rollback it
+            tx.Commit();
+
+            _logger.Information("Registered switch {Switch} in system {System} with members {@Members}", sw.Id, system.Id, members.Select(m => m.Id));
         }
 
         public IAsyncEnumerable<PKSwitch> GetSwitches(PKSystem system)
@@ -276,8 +275,8 @@ namespace PluralKit.Core {
         public async IAsyncEnumerable<SwitchMembersListEntry> GetSwitchMembersList(PKSystem system, Instant start, Instant end)
         {
             // Wrap multiple commands in a single transaction for performance
-            using var conn = await _conn.Obtain();
-            using var tx = conn.BeginTransaction();
+            await using var conn = await _conn.Obtain();
+            await using var tx = await conn.BeginTransactionAsync();
             
             // Find the time of the last switch outside the range as it overlaps the range
             // If no prior switch exists, the lower bound of the range remains the start time

PluralKit.Core/Utils/BulkImporter.cs

@@ -3,6 +3,7 @@ using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Data;
+using System.Data.Common;
 using System.Linq;
 using System.Threading.Tasks;
 
@@ -19,20 +20,20 @@ namespace PluralKit.Core
     public class BulkImporter: IAsyncDisposable
     {
         private readonly int _systemId;
-        private readonly NpgsqlConnection _conn;
-        private readonly NpgsqlTransaction _tx;
+        private readonly IPKConnection _conn;
+        private readonly DbTransaction _tx;
         private readonly Dictionary<string, int> _knownMembers = new Dictionary<string, int>();
         private readonly Dictionary<string, PKMember> _existingMembersByHid = new Dictionary<string, PKMember>();
         private readonly Dictionary<string, PKMember> _existingMembersByName = new Dictionary<string, PKMember>();
 
-        private BulkImporter(int systemId, NpgsqlConnection conn, NpgsqlTransaction tx)
+        private BulkImporter(int systemId, IPKConnection conn, DbTransaction tx)
         {
             _systemId = systemId;
             _conn = conn;
             _tx = tx;
         }
 
-        public static async Task<BulkImporter> Begin(PKSystem system, NpgsqlConnection conn)
+        public static async Task<BulkImporter> Begin(PKSystem system, IPKConnection conn)
         {
             var tx = await conn.BeginTransactionAsync();
             var importer = new BulkImporter(system.Id, conn, tx);

PluralKit.Core/Utils/ConnectionUtils.cs

@@ -7,21 +7,21 @@ using Dapper;
 namespace PluralKit.Core {
     public static class ConnectionUtils
     {
-        public static async IAsyncEnumerable<T> QueryStreamAsync<T>(this DbConnectionFactory connFactory, string sql, object param)
+        public static async IAsyncEnumerable<T> QueryStreamAsync<T>(this Database connFactory, string sql, object param)
         {
-            using var conn = await connFactory.Obtain();
+            await using var conn = await connFactory.Obtain();
             
             await using var reader = (DbDataReader) await conn.ExecuteReaderAsync(sql, param);
             var parser = reader.GetRowParser<T>();
-            while (reader.Read())
+            while (await reader.ReadAsync())
                 yield return parser(reader); 
         }
         
-        public static async IAsyncEnumerable<T> QueryStreamAsync<T>(this IDbConnection conn, string sql, object param)
+        public static async IAsyncEnumerable<T> QueryStreamAsync<T>(this IPKConnection conn, string sql, object param)
         {
             await using var reader = (DbDataReader) await conn.ExecuteReaderAsync(sql, param);
             var parser = reader.GetRowParser<T>();
-            while (reader.Read())
+            while (await reader.ReadAsync())
                 yield return parser(reader); 
         }
     }

PluralKit.Core/Utils/DatabaseUtils.cs

@@ -1,234 +1,10 @@
-using System;
-using System.Data;
-using System.Data.Common;
-using System.Diagnostics;
+using System.Data;
 using System.Threading;
-using System.Threading.Tasks;
-
-using App.Metrics;
 
 using Dapper;
 
-using Npgsql;
-
-using Serilog;
-
 namespace PluralKit.Core
 {
-    public class QueryLogger : IDisposable
-    {
-        private ILogger _logger;
-        private IMetrics _metrics;
-        private string _commandText;
-        private Stopwatch _stopwatch;
-
-        public QueryLogger(ILogger logger, IMetrics metrics, string commandText)
-        {
-            _metrics = metrics;
-            _commandText = commandText;
-            _logger = logger;
-            
-            _stopwatch = new Stopwatch();
-            _stopwatch.Start();
-        }
-
-        public void Dispose()
-        {
-            _stopwatch.Stop();
-            _logger.Verbose("Executed query {Query} in {ElapsedTime}", _commandText, _stopwatch.Elapsed);
-            
-            // One tick is 100 nanoseconds
-            _metrics.Provider.Timer.Instance(CoreMetrics.DatabaseQuery, new MetricTags("query", _commandText))
-                .Record(_stopwatch.ElapsedTicks / 10, TimeUnit.Microseconds, _commandText);
-        }
-    }
-
-    public class PerformanceTrackingCommand: DbCommand
-    {
-        private NpgsqlCommand _impl;
-        private ILogger _logger;
-        private IMetrics _metrics;
-
-        public PerformanceTrackingCommand(NpgsqlCommand impl, ILogger logger, IMetrics metrics)
-        {
-            _impl = impl;
-            _metrics = metrics;
-            _logger = logger;
-        }
-
-        public override void Cancel()
-        {
-            _impl.Cancel();
-        }
-
-        public override int ExecuteNonQuery()
-        {
-            return _impl.ExecuteNonQuery();
-        }
-
-        public override object ExecuteScalar()
-        {
-            return _impl.ExecuteScalar();
-        }
-
-        public override void Prepare()
-        {
-            _impl.Prepare();
-        }
-
-        public override string CommandText
-        {
-            get => _impl.CommandText;
-            set => _impl.CommandText = value;
-        }
-
-        public override int CommandTimeout
-        {
-            get => _impl.CommandTimeout;
-            set => _impl.CommandTimeout = value;
-        }
-
-        public override CommandType CommandType
-        {
-            get => _impl.CommandType;
-            set => _impl.CommandType = value;
-        }
-
-        public override UpdateRowSource UpdatedRowSource
-        {
-            get => _impl.UpdatedRowSource;
-            set => _impl.UpdatedRowSource = value;
-        }
-
-        protected override DbConnection DbConnection
-        {
-            get => _impl.Connection;
-            set => _impl.Connection = (NpgsqlConnection) value;
-        }
-
-        protected override DbParameterCollection DbParameterCollection => _impl.Parameters;
-
-        protected override DbTransaction DbTransaction
-        {
-            get => _impl.Transaction;
-            set => _impl.Transaction = (NpgsqlTransaction) value;
-        }
-
-        public override bool DesignTimeVisible
-        {
-            get => _impl.DesignTimeVisible;
-            set => _impl.DesignTimeVisible = value;
-        }
-
-        protected override DbParameter CreateDbParameter()
-        {
-            return _impl.CreateParameter();
-        }
-
-        protected override DbDataReader ExecuteDbDataReader(CommandBehavior behavior)
-        {
-            return _impl.ExecuteReader(behavior);
-        }
-
-        private IDisposable LogQuery()
-        {
-            return new QueryLogger(_logger, _metrics, CommandText);
-        }
-
-        protected override async Task<DbDataReader> ExecuteDbDataReaderAsync(
-            CommandBehavior behavior, CancellationToken cancellationToken)
-        {
-            using (LogQuery())
-                return await _impl.ExecuteReaderAsync(behavior, cancellationToken);
-        }
-
-        public override async Task<int> ExecuteNonQueryAsync(CancellationToken cancellationToken)
-        {
-            using (LogQuery())
-                return await _impl.ExecuteNonQueryAsync(cancellationToken);
-        }
-
-        public override async Task<object> ExecuteScalarAsync(CancellationToken cancellationToken)
-        {
-            using (LogQuery())
-                return await _impl.ExecuteScalarAsync(cancellationToken);
-        }
-    }
-
-    public class PerformanceTrackingConnection: IAsyncDbConnection
-    {
-        // Simple delegation of everything.
-        internal NpgsqlConnection _impl;
-
-        private DbConnectionCountHolder _countHolder;
-        private ILogger _logger;
-        private IMetrics _metrics;
-
-        public PerformanceTrackingConnection(NpgsqlConnection impl, DbConnectionCountHolder countHolder,
-                                             ILogger logger, IMetrics metrics)
-        {
-            _impl = impl;
-            _countHolder = countHolder;
-            _logger = logger;
-            _metrics = metrics;
-        }
-
-        public void Dispose()
-        {
-            _impl.Dispose();
-
-            _countHolder.Decrement();
-        }
-
-        public IDbTransaction BeginTransaction()
-        {
-            return _impl.BeginTransaction();
-        }
-
-        public IDbTransaction BeginTransaction(IsolationLevel il)
-        {
-            return _impl.BeginTransaction(il);
-        }
-
-        public void ChangeDatabase(string databaseName)
-        {
-            _impl.ChangeDatabase(databaseName);
-        }
-
-        public void Close()
-        {
-            _impl.Close();
-        }
-
-        public IDbCommand CreateCommand()
-        {
-            return new PerformanceTrackingCommand(_impl.CreateCommand(), _logger, _metrics);
-        }
-
-        public void Open()
-        {
-            _impl.Open();
-        }
-
-        public NpgsqlBinaryImporter BeginBinaryImport(string copyFromCommand)
-        {
-            return _impl.BeginBinaryImport(copyFromCommand);
-        }
-
-        public string ConnectionString
-        {
-            get => _impl.ConnectionString;
-            set => _impl.ConnectionString = value;
-        }
-
-        public int ConnectionTimeout => _impl.ConnectionTimeout;
-
-        public string Database => _impl.Database;
-
-        public ConnectionState State => _impl.State;
-        public ValueTask DisposeAsync() => _impl.DisposeAsync();
-    }
-
     public class DbConnectionCountHolder
     {
         private int _connectionCount;
@@ -245,43 +21,6 @@ namespace PluralKit.Core
         }
     }
 
-    public interface IAsyncDbConnection: IDbConnection, IAsyncDisposable
-    {
-        
-    }
-
-    public class DbConnectionFactory
-    {
-        private CoreConfig _config;
-        private ILogger _logger;
-        private IMetrics _metrics;
-        private DbConnectionCountHolder _countHolder;
-
-        public DbConnectionFactory(CoreConfig config, DbConnectionCountHolder countHolder, ILogger logger,
-                                   IMetrics metrics)
-        {
-            _config = config;
-            _countHolder = countHolder;
-            _metrics = metrics;
-            _logger = logger;
-        }
-
-        public async Task<IAsyncDbConnection> Obtain()
-        {
-            // Mark the request (for a handle, I guess) in the metrics
-            _metrics.Measure.Meter.Mark(CoreMetrics.DatabaseRequests);
-
-            // Actually create and try to open the connection
-            var conn = new NpgsqlConnection(_config.Database);
-            await conn.OpenAsync();
-
-            // Increment the count
-            _countHolder.Increment();
-            // Return a wrapped connection which will decrement the counter on dispose
-            return new PerformanceTrackingConnection(conn, _countHolder, _logger, _metrics);
-        }
-    }
-
     public class PassthroughTypeHandler<T>: SqlMapper.TypeHandler<T>
     {
         public override void SetValue(IDbDataParameter parameter, T value)
@@ -308,18 +47,4 @@ namespace PluralKit.Core
             parameter.Value = (long) value;
         }
     }
-
-    public static class DatabaseExt
-    {
-        public static async Task Execute(this DbConnectionFactory db, Func<IDbConnection, Task> func)
-        {
-            await using var conn = await db.Obtain();
-            await func(conn);
-        }
-        public static async Task<T> Execute<T>(this DbConnectionFactory db, Func<IDbConnection, Task<T>> func)
-        {
-            await using var conn = await db.Obtain();
-            return await func(conn);
-        }
-    }
 }