Rewrite database interface to be asynchronous and improve UI

app/Desktop/Main/Controls/StatusBarModel.cs

@@ -34,7 +34,7 @@ sealed class StatusBarModel : BaseModel, IDisposable {
 	}
 
 	public void Dispose() {
-		state.Server.StatusChanged -= OnServerStatusChanged;
+		state.Server.StatusChanged += OnServerStatusChanged;
 	}
 
 	private void OnServerStatusChanged(object? sender, ServerManager.Status e) {

app/Desktop/Main/Pages/AttachmentsPageModel.cs

@@ -69,12 +69,12 @@ sealed class AttachmentsPageModel : BaseModel, IDisposable {
 	public bool HasFailedDownloads => statisticsFailed.Items > 0;
 
 	private readonly State state;
-	private readonly ThrottledTask<int> enqueueDownloadItemsTask;
+	private readonly ThrottledTask enqueueDownloadItemsTask;
 	private readonly ThrottledTask<DownloadStatusStatistics> downloadStatisticsTask;
 
 	private IDisposable? finishedItemsSubscription;
 	private int doneItemsCount;
-	private int totalEnqueuedItemCount;
+	private int initialFinishedCount;
 	private int? totalItemsToDownloadCount;
 
 	public AttachmentsPageModel() : this(State.Dummy) {}
@@ -84,7 +84,7 @@ sealed class AttachmentsPageModel : BaseModel, IDisposable {
 
 		FilterModel = new AttachmentFilterPanelModel(state);
 
-		enqueueDownloadItemsTask = new ThrottledTask<int>(OnItemsEnqueued, TaskScheduler.FromCurrentSynchronizationContext());
+		enqueueDownloadItemsTask = new ThrottledTask(RecomputeDownloadStatistics, TaskScheduler.FromCurrentSynchronizationContext());
 		downloadStatisticsTask = new ThrottledTask<DownloadStatusStatistics>(UpdateStatistics, TaskScheduler.FromCurrentSynchronizationContext());
 		RecomputeDownloadStatistics();
 
@@ -93,7 +93,6 @@ sealed class AttachmentsPageModel : BaseModel, IDisposable {
 
 	public void Dispose() {
 		state.Db.Statistics.PropertyChanged -= OnDbStatisticsChanged;
-		enqueueDownloadItemsTask.Dispose();
 		downloadStatisticsTask.Dispose();
 		finishedItemsSubscription?.Dispose();
 		FilterModel.Dispose();
@@ -114,7 +113,7 @@ sealed class AttachmentsPageModel : BaseModel, IDisposable {
 	}
 
 	private async Task EnqueueDownloadItems() {
-		OnItemsEnqueued(await state.Db.Downloads.EnqueueDownloadItems(CreateAttachmentFilter()));
+		await state.Db.Downloads.EnqueueDownloadItems(CreateAttachmentFilter());
 	}
 
 	private void EnqueueDownloadItemsLater() {
@@ -122,19 +121,49 @@ sealed class AttachmentsPageModel : BaseModel, IDisposable {
 		enqueueDownloadItemsTask.Post(cancellationToken => state.Db.Downloads.EnqueueDownloadItems(filter, cancellationToken));
 	}
 
-	private void OnItemsEnqueued(int itemCount) {
-		totalEnqueuedItemCount += itemCount;
-		totalItemsToDownloadCount = totalEnqueuedItemCount;
-		UpdateDownloadMessage();
-		RecomputeDownloadStatistics();
-	}
-
 	private AttachmentFilter CreateAttachmentFilter() {
 		var filter = FilterModel.CreateFilter();
 		filter.DownloadItemRule = AttachmentFilter.DownloadItemRules.OnlyNotPresent;
 		return filter;
 	}
 
+	private void RecomputeDownloadStatistics() {
+		downloadStatisticsTask.Post(state.Db.Downloads.GetStatistics);
+	}
+
+	private void UpdateStatistics(DownloadStatusStatistics statusStatistics) {
+		var hadFailedDownloads = HasFailedDownloads;
+
+		statisticsEnqueued.Items = statusStatistics.EnqueuedCount;
+		statisticsEnqueued.Size = statusStatistics.EnqueuedSize;
+
+		statisticsDownloaded.Items = statusStatistics.SuccessfulCount;
+		statisticsDownloaded.Size = statusStatistics.SuccessfulSize;
+
+		statisticsFailed.Items = statusStatistics.FailedCount;
+		statisticsFailed.Size = statusStatistics.FailedSize;
+
+		statisticsSkipped.Items = statusStatistics.SkippedCount;
+		statisticsSkipped.Size = statusStatistics.SkippedSize;
+
+		OnPropertyChanged(nameof(StatisticsRows));
+
+		if (hadFailedDownloads != HasFailedDownloads) {
+			OnPropertyChanged(nameof(HasFailedDownloads));
+			OnPropertyChanged(nameof(IsRetryFailedOnDownloadsButtonEnabled));
+		}
+
+		totalItemsToDownloadCount = statisticsEnqueued.Items + statisticsDownloaded.Items + statisticsFailed.Items - initialFinishedCount;
+		UpdateDownloadMessage();
+	}
+
+	private void UpdateDownloadMessage() {
+		DownloadMessage = IsDownloading ? doneItemsCount.Format() + " / " + (totalItemsToDownloadCount?.Format() ?? "?") : "";
+
+		OnPropertyChanged(nameof(DownloadMessage));
+		OnPropertyChanged(nameof(DownloadProgress));
+	}
+
 	public async Task OnClickToggleDownload() {
 		IsToggleDownloadButtonEnabled = false;
 
@@ -149,13 +178,14 @@ sealed class AttachmentsPageModel : BaseModel, IDisposable {
 			await state.Db.Downloads.RemoveDownloadItems(EnqueuedItemFilter, FilterRemovalMode.RemoveMatching);
 
 			doneItemsCount = 0;
-			totalEnqueuedItemCount = 0;
+			initialFinishedCount = 0;
 			totalItemsToDownloadCount = null;
 			UpdateDownloadMessage();
 		}
 		else {
 			var finishedItems = await state.Downloader.Start();
 
+			initialFinishedCount = statisticsDownloaded.Items + statisticsFailed.Items;
 			finishedItemsSubscription = finishedItems.Select(static _ => true)
 			                                         .Buffer(TimeSpan.FromMilliseconds(100))
 			                                         .Select(static items => items.Count)
@@ -201,42 +231,6 @@ sealed class AttachmentsPageModel : BaseModel, IDisposable {
 		}
 	}
 
-	private void RecomputeDownloadStatistics() {
-		downloadStatisticsTask.Post(state.Db.Downloads.GetStatistics);
-	}
-
-	private void UpdateStatistics(DownloadStatusStatistics statusStatistics) {
-		var hadFailedDownloads = HasFailedDownloads;
-
-		statisticsEnqueued.Items = statusStatistics.EnqueuedCount;
-		statisticsEnqueued.Size = statusStatistics.EnqueuedSize;
-
-		statisticsDownloaded.Items = statusStatistics.SuccessfulCount;
-		statisticsDownloaded.Size = statusStatistics.SuccessfulSize;
-
-		statisticsFailed.Items = statusStatistics.FailedCount;
-		statisticsFailed.Size = statusStatistics.FailedSize;
-
-		statisticsSkipped.Items = statusStatistics.SkippedCount;
-		statisticsSkipped.Size = statusStatistics.SkippedSize;
-
-		OnPropertyChanged(nameof(StatisticsRows));
-
-		if (hadFailedDownloads != HasFailedDownloads) {
-			OnPropertyChanged(nameof(HasFailedDownloads));
-			OnPropertyChanged(nameof(IsRetryFailedOnDownloadsButtonEnabled));
-		}
-
-		UpdateDownloadMessage();
-	}
-
-	private void UpdateDownloadMessage() {
-		DownloadMessage = IsDownloading ? doneItemsCount.Format() + " / " + (totalItemsToDownloadCount?.Format() ?? "?") : "";
-
-		OnPropertyChanged(nameof(DownloadMessage));
-		OnPropertyChanged(nameof(DownloadProgress));
-	}
-
 	public sealed class StatisticsRow {
 		public string State { get; }
 		public int Items { get; set; }

app/Server/Database/Repositories/IDownloadRepository.cs

@@ -22,7 +22,7 @@ public interface IDownloadRepository {
 
 	Task<DownloadedAttachment?> GetDownloadedAttachment(string normalizedUrl);
 
-	Task<int> EnqueueDownloadItems(AttachmentFilter? filter = null, CancellationToken cancellationToken = default);
+	Task EnqueueDownloadItems(AttachmentFilter? filter = null, CancellationToken cancellationToken = default);
 
 	IAsyncEnumerable<DownloadItem> PullEnqueuedDownloadItems(int count, CancellationToken cancellationToken = default);
 
@@ -53,8 +53,8 @@ public interface IDownloadRepository {
 			return Task.FromResult<DownloadedAttachment?>(null);
 		}
 
-		public Task<int> EnqueueDownloadItems(AttachmentFilter? filter, CancellationToken cancellationToken) {
-			return Task.FromResult(0);
+		public Task EnqueueDownloadItems(AttachmentFilter? filter, CancellationToken cancellationToken) {
+			return Task.CompletedTask;
 		}
 
 		public IAsyncEnumerable<DownloadItem> PullEnqueuedDownloadItems(int count, CancellationToken cancellationToken) {

app/Server/Database/Sqlite/Repositories/SqliteDownloadRepository.cs

@@ -164,7 +164,7 @@ sealed class SqliteDownloadRepository : IDownloadRepository {
 		};
 	}
 
-	public async Task<int> EnqueueDownloadItems(AttachmentFilter? filter, CancellationToken cancellationToken) {
+	public async Task EnqueueDownloadItems(AttachmentFilter? filter, CancellationToken cancellationToken) {
 		using var conn = pool.Take();
 
 		await using var cmd = conn.Command(
@@ -178,7 +178,7 @@ sealed class SqliteDownloadRepository : IDownloadRepository {
 		);
 
 		cmd.AddAndSet(":enqueued", SqliteType.Integer, (int) DownloadStatus.Enqueued);
-		return await cmd.ExecuteNonQueryAsync(cancellationToken);
+		await cmd.ExecuteNonQueryAsync(cancellationToken);
 	}
 
 	public async IAsyncEnumerable<DownloadItem> PullEnqueuedDownloadItems(int count, [EnumeratorCancellation] CancellationToken cancellationToken) {

app/Server/Database/Sqlite/Schema.cs

@@ -21,14 +21,14 @@ sealed class Schema {
 	}
 
 	public async Task<bool> Setup(ISchemaUpgradeCallbacks callbacks) {
-		await conn.ExecuteAsync("CREATE TABLE IF NOT EXISTS metadata (key TEXT PRIMARY KEY, value TEXT)");
+		conn.Execute(@"CREATE TABLE IF NOT EXISTS metadata (key TEXT PRIMARY KEY, value TEXT)");
 
-		var dbVersionStr = await conn.ExecuteReaderAsync("SELECT value FROM metadata WHERE key = 'version'", static reader => reader?.GetString(0));
+		var dbVersionStr = conn.SelectScalar("SELECT value FROM metadata WHERE key = 'version'");
 		if (dbVersionStr == null) {
-			await InitializeSchemas();
+			InitializeSchemas();
 		}
-		else if (!int.TryParse(dbVersionStr, out int dbVersion) || dbVersion < 1) {
-			throw new InvalidDatabaseVersionException(dbVersionStr);
+		else if (!int.TryParse(dbVersionStr.ToString(), out int dbVersion) || dbVersion < 1) {
+			throw new InvalidDatabaseVersionException(dbVersionStr.ToString() ?? "<null>");
 		}
 		else if (dbVersion > Version) {
 			throw new DatabaseTooNewException(dbVersion);
@@ -45,123 +45,123 @@ sealed class Schema {
 		return true;
 	}
 
-	private async Task InitializeSchemas() {
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE users (
-		                        	id            INTEGER PRIMARY KEY NOT NULL,
-		                        	name          TEXT NOT NULL,
-		                        	avatar_url    TEXT,
-		                        	discriminator TEXT
-		                        )
-		                        """);
+	private void InitializeSchemas() {
+		conn.Execute("""
+		             CREATE TABLE users (
+		             	id            INTEGER PRIMARY KEY NOT NULL,
+		             	name          TEXT NOT NULL,
+		             	avatar_url    TEXT,
+		             	discriminator TEXT
+		             )
+		             """);
 
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE servers (
-		                        	id   INTEGER PRIMARY KEY NOT NULL,
-		                        	name TEXT NOT NULL,
-		                        	type TEXT NOT NULL
-		                        )
-		                        """);
+		conn.Execute("""
+		             CREATE TABLE servers (
+		             	id   INTEGER PRIMARY KEY NOT NULL,
+		             	name TEXT NOT NULL,
+		             	type TEXT NOT NULL
+		             )
+		             """);
 
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE channels (
-		                        	id        INTEGER PRIMARY KEY NOT NULL,
-		                        	server    INTEGER NOT NULL,
-		                        	name      TEXT NOT NULL,
-		                        	parent_id INTEGER,
-		                        	position  INTEGER,
-		                        	topic     TEXT,
-		                        	nsfw      INTEGER
-		                        )
-		                        """);
+		conn.Execute("""
+		             CREATE TABLE channels (
+		             	id        INTEGER PRIMARY KEY NOT NULL,
+		             	server    INTEGER NOT NULL,
+		             	name      TEXT NOT NULL,
+		             	parent_id INTEGER,
+		             	position  INTEGER,
+		             	topic     TEXT,
+		             	nsfw      INTEGER
+		             )
+		             """);
 
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE messages (
-		                        	message_id INTEGER PRIMARY KEY NOT NULL,
-		                        	sender_id  INTEGER NOT NULL,
-		                        	channel_id INTEGER NOT NULL,
-		                        	text       TEXT NOT NULL,
-		                        	timestamp  INTEGER NOT NULL
-		                        )
-		                        """);
+		conn.Execute("""
+		             CREATE TABLE messages (
+		             	message_id INTEGER PRIMARY KEY NOT NULL,
+		             	sender_id  INTEGER NOT NULL,
+		             	channel_id INTEGER NOT NULL,
+		             	text       TEXT NOT NULL,
+		             	timestamp  INTEGER NOT NULL
+		             )
+		             """);
 
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE attachments (
-		                        	message_id     INTEGER NOT NULL,
-		                        	attachment_id  INTEGER NOT NULL PRIMARY KEY NOT NULL,
-		                        	name           TEXT NOT NULL,
-		                        	type           TEXT,
-		                        	normalized_url TEXT NOT NULL,
-		                        	download_url   TEXT,
-		                        	size           INTEGER NOT NULL,
-		                        	width          INTEGER,
-		                        	height         INTEGER
-		                        )
-		                        """);
+		conn.Execute("""
+		             CREATE TABLE attachments (
+		             	message_id     INTEGER NOT NULL,
+		             	attachment_id  INTEGER NOT NULL PRIMARY KEY NOT NULL,
+		             	name           TEXT NOT NULL,
+		             	type           TEXT,
+		             	normalized_url TEXT NOT NULL,
+		             	download_url   TEXT,
+		             	size           INTEGER NOT NULL,
+		             	width          INTEGER,
+		             	height         INTEGER
+		             )
+		             """);
 
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE embeds (
-		                        	message_id INTEGER NOT NULL,
-		                        	json       TEXT NOT NULL
-		                        )
-		                        """);
+		conn.Execute("""
+		             CREATE TABLE embeds (
+		             	message_id INTEGER NOT NULL,
+		             	json       TEXT NOT NULL
+		             )
+		             """);
 
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE downloads (
-		                        	normalized_url TEXT NOT NULL PRIMARY KEY,
-		                        	download_url   TEXT,
-		                        	status         INTEGER NOT NULL,
-		                        	size           INTEGER NOT NULL,
-		                        	blob           BLOB
-		                        )
-		                        """);
+		conn.Execute("""
+		             CREATE TABLE downloads (
+		             	normalized_url TEXT NOT NULL PRIMARY KEY,
+		             	download_url   TEXT,
+		             	status         INTEGER NOT NULL,
+		             	size           INTEGER NOT NULL,
+		             	blob           BLOB
+		             )
+		             """);
+		
+		conn.Execute("""
+		             CREATE TABLE reactions (
+		             	message_id  INTEGER NOT NULL,
+		             	emoji_id    INTEGER,
+		             	emoji_name  TEXT,
+		             	emoji_flags INTEGER NOT NULL,
+		             	count       INTEGER NOT NULL
+		             )
+		             """);
 
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE reactions (
-		                        	message_id  INTEGER NOT NULL,
-		                        	emoji_id    INTEGER,
-		                        	emoji_name  TEXT,
-		                        	emoji_flags INTEGER NOT NULL,
-		                        	count       INTEGER NOT NULL
-		                        )
-		                        """);
+		CreateMessageEditTimestampTable();
+		CreateMessageRepliedToTable();
 
-		await CreateMessageEditTimestampTable();
-		await CreateMessageRepliedToTable();
+		conn.Execute("CREATE INDEX attachments_message_ix ON attachments(message_id)");
+		conn.Execute("CREATE INDEX embeds_message_ix ON embeds(message_id)");
+		conn.Execute("CREATE INDEX reactions_message_ix ON reactions(message_id)");
 
-		await conn.ExecuteAsync("CREATE INDEX attachments_message_ix ON attachments(message_id)");
-		await conn.ExecuteAsync("CREATE INDEX embeds_message_ix ON embeds(message_id)");
-		await conn.ExecuteAsync("CREATE INDEX reactions_message_ix ON reactions(message_id)");
-
-		await conn.ExecuteAsync("INSERT INTO metadata (key, value) VALUES ('version', " + Version + ")");
+		conn.Execute("INSERT INTO metadata (key, value) VALUES ('version', " + Version + ")");
 	}
 
-	private async Task CreateMessageEditTimestampTable() {
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE edit_timestamps (
-		                        	message_id     INTEGER PRIMARY KEY NOT NULL,
-		                        	edit_timestamp INTEGER NOT NULL
-		                        )
-		                        """);
+	private void CreateMessageEditTimestampTable() {
+		conn.Execute("""
+		             CREATE TABLE edit_timestamps (
+		             	message_id     INTEGER PRIMARY KEY NOT NULL,
+		             	edit_timestamp INTEGER NOT NULL
+		             )
+		             """);
 	}
 
-	private async Task CreateMessageRepliedToTable() {
-		await conn.ExecuteAsync("""
-		                        CREATE TABLE replied_to (
-		                        	message_id    INTEGER PRIMARY KEY NOT NULL,
-		                        	replied_to_id INTEGER NOT NULL
-		                        )
-		                        """);
+	private void CreateMessageRepliedToTable() {
+		conn.Execute("""
+		             CREATE TABLE replied_to (
+		             	message_id    INTEGER PRIMARY KEY NOT NULL,
+		             	replied_to_id INTEGER NOT NULL
+		             )
+		             """);
 	}
 
 	private async Task NormalizeAttachmentUrls(ISchemaUpgradeCallbacks.IProgressReporter reporter) {
 		await reporter.SubWork("Preparing attachments...", 0, 0);
-
+		
 		var normalizedUrls = new Dictionary<long, string>();
 
 		await using (var selectCmd = conn.Command("SELECT attachment_id, url FROM attachments")) {
 			await using var reader = await selectCmd.ExecuteReaderAsync();
-
+			
 			while (reader.Read()) {
 				var attachmentId = reader.GetInt64(0);
 				var originalUrl = reader.GetString(1);
@@ -177,7 +177,7 @@ sealed class Schema {
 		await using (var updateCmd = conn.Command("UPDATE attachments SET download_url = url, url = :normalized_url WHERE attachment_id = :attachment_id")) {
 			updateCmd.Add(":attachment_id", SqliteType.Integer);
 			updateCmd.Add(":normalized_url", SqliteType.Text);
-
+				
 			foreach (var (attachmentId, normalizedUrl) in normalizedUrls) {
 				if (++processedUrls % 1000 == 0) {
 					await reporter.SubWork("Updating URLs...", processedUrls, totalUrls);
@@ -188,15 +188,15 @@ sealed class Schema {
 				updateCmd.ExecuteNonQuery();
 			}
 		}
-
+		
 		await reporter.SubWork("Updating URLs...", totalUrls, totalUrls);
-
+		
 		await tx.CommitAsync();
 	}
 
 	private async Task NormalizeDownloadUrls(ISchemaUpgradeCallbacks.IProgressReporter reporter) {
 		await reporter.SubWork("Preparing downloads...", 0, 0);
-
+		
 		var normalizedUrlsToOriginalUrls = new Dictionary<string, string>();
 		var duplicateUrlsToDelete = new HashSet<string>();
 
@@ -213,10 +213,10 @@ sealed class Schema {
 			}
 		}
 
-		await conn.ExecuteAsync("PRAGMA cache_size = -20000");
+		conn.Execute("PRAGMA cache_size = -20000");
 
 		DbTransaction tx;
-
+		
 		await using (tx = await conn.BeginTransactionAsync()) {
 			await reporter.SubWork("Deleting duplicates...", 0, 0);
 
@@ -226,7 +226,7 @@ sealed class Schema {
 					deleteCmd.ExecuteNonQuery();
 				}
 			}
-
+			
 			await tx.CommitAsync();
 		}
 
@@ -234,20 +234,20 @@ sealed class Schema {
 		int processedUrls = -1;
 
 		tx = await conn.BeginTransactionAsync();
-
+		
 		await using (var updateCmd = conn.Command("UPDATE downloads SET download_url = :download_url, url = :normalized_url WHERE url = :download_url")) {
 			updateCmd.Add(":normalized_url", SqliteType.Text);
 			updateCmd.Add(":download_url", SqliteType.Text);
-
+			
 			foreach (var (normalizedUrl, downloadUrl) in normalizedUrlsToOriginalUrls) {
 				if (++processedUrls % 100 == 0) {
 					await reporter.SubWork("Updating URLs...", processedUrls, totalUrls);
-
+					
 					// Not proper way of dealing with transactions, but it avoids a long commit at the end.
 					// Schema upgrades are already non-atomic anyways, so this doesn't make it worse.
 					await tx.CommitAsync();
 					await tx.DisposeAsync();
-
+					
 					tx = await conn.BeginTransactionAsync();
 					updateCmd.Transaction = (SqliteTransaction) tx;
 				}
@@ -257,98 +257,98 @@ sealed class Schema {
 				updateCmd.ExecuteNonQuery();
 			}
 		}
-
+		
 		await reporter.SubWork("Updating URLs...", totalUrls, totalUrls);
-
+		
 		await tx.CommitAsync();
 		await tx.DisposeAsync();
-
-		await conn.ExecuteAsync("PRAGMA cache_size = -2000");
+		
+		conn.Execute("PRAGMA cache_size = -2000");
 	}
 
 	private async Task UpgradeSchemas(int dbVersion, ISchemaUpgradeCallbacks.IProgressReporter reporter) {
 		var perf = Log.Start("from version " + dbVersion);
 
-		await conn.ExecuteAsync("UPDATE metadata SET value = " + Version + " WHERE key = 'version'");
+		conn.Execute("UPDATE metadata SET value = " + Version + " WHERE key = 'version'");
 
 		if (dbVersion <= 1) {
 			await reporter.MainWork("Applying schema changes...", 0, 1);
-			await conn.ExecuteAsync("ALTER TABLE channels ADD parent_id INTEGER");
-
+			conn.Execute("ALTER TABLE channels ADD parent_id INTEGER");
+			
 			perf.Step("Upgrade to version 2");
 			await reporter.NextVersion();
 		}
 
 		if (dbVersion <= 2) {
 			await reporter.MainWork("Applying schema changes...", 0, 1);
+			
+			CreateMessageEditTimestampTable();
+			CreateMessageRepliedToTable();
 
-			await CreateMessageEditTimestampTable();
-			await CreateMessageRepliedToTable();
+			conn.Execute("""
+			             INSERT INTO edit_timestamps (message_id, edit_timestamp)
+			             SELECT message_id, edit_timestamp
+			             FROM messages
+			             WHERE edit_timestamp IS NOT NULL
+			             """);
 
-			await conn.ExecuteAsync("""
-			                        INSERT INTO edit_timestamps (message_id, edit_timestamp)
-			                        SELECT message_id, edit_timestamp
-			                        FROM messages
-			                        WHERE edit_timestamp IS NOT NULL
-			                        """);
+			conn.Execute("""
+			             INSERT INTO replied_to (message_id, replied_to_id)
+			             SELECT message_id, replied_to_id
+			             FROM messages
+			             WHERE replied_to_id IS NOT NULL
+			             """);
 
-			await conn.ExecuteAsync("""
-			                        INSERT INTO replied_to (message_id, replied_to_id)
-			                        SELECT message_id, replied_to_id
-			                        FROM messages
-			                        WHERE replied_to_id IS NOT NULL
-			                        """);
-
-			await conn.ExecuteAsync("ALTER TABLE messages DROP COLUMN replied_to_id");
-			await conn.ExecuteAsync("ALTER TABLE messages DROP COLUMN edit_timestamp");
+			conn.Execute("ALTER TABLE messages DROP COLUMN replied_to_id");
+			conn.Execute("ALTER TABLE messages DROP COLUMN edit_timestamp");
 
 			perf.Step("Upgrade to version 3");
-
+			
 			await reporter.MainWork("Vacuuming the database...", 1, 1);
-			await conn.ExecuteAsync("VACUUM");
+			conn.Execute("VACUUM");
 			perf.Step("Vacuum");
-
+			
 			await reporter.NextVersion();
 		}
 
 		if (dbVersion <= 3) {
-			await conn.ExecuteAsync("""
-			                        CREATE TABLE downloads (
-			                        	url    TEXT NOT NULL PRIMARY KEY,
-			                        	status INTEGER NOT NULL,
-			                        	size   INTEGER NOT NULL,
-			                        	blob   BLOB
-			                        )
-			                        """);
-
+			conn.Execute("""
+			             CREATE TABLE downloads (
+			             	url    TEXT NOT NULL PRIMARY KEY,
+			             	status INTEGER NOT NULL,
+			             	size   INTEGER NOT NULL,
+			             	blob   BLOB
+			             )
+			             """);
+			
 			perf.Step("Upgrade to version 4");
 			await reporter.NextVersion();
 		}
 
 		if (dbVersion <= 4) {
 			await reporter.MainWork("Applying schema changes...", 0, 1);
-			await conn.ExecuteAsync("ALTER TABLE attachments ADD width INTEGER");
-			await conn.ExecuteAsync("ALTER TABLE attachments ADD height INTEGER");
-
+			conn.Execute("ALTER TABLE attachments ADD width INTEGER");
+			conn.Execute("ALTER TABLE attachments ADD height INTEGER");
+			
 			perf.Step("Upgrade to version 5");
 			await reporter.NextVersion();
 		}
 
 		if (dbVersion <= 5) {
 			await reporter.MainWork("Applying schema changes...", 0, 3);
-			await conn.ExecuteAsync("ALTER TABLE attachments ADD download_url TEXT");
-			await conn.ExecuteAsync("ALTER TABLE downloads ADD download_url TEXT");
-
+			conn.Execute("ALTER TABLE attachments ADD download_url TEXT");
+			conn.Execute("ALTER TABLE downloads ADD download_url TEXT");
+			
 			await reporter.MainWork("Updating attachments...", 1, 3);
 			await NormalizeAttachmentUrls(reporter);
-
+			
 			await reporter.MainWork("Updating downloads...", 2, 3);
 			await NormalizeDownloadUrls(reporter);
-
+			
 			await reporter.MainWork("Applying schema changes...", 3, 3);
-			await conn.ExecuteAsync("ALTER TABLE attachments RENAME COLUMN url TO normalized_url");
-			await conn.ExecuteAsync("ALTER TABLE downloads RENAME COLUMN url TO normalized_url");
-
+			conn.Execute("ALTER TABLE attachments RENAME COLUMN url TO normalized_url");
+			conn.Execute("ALTER TABLE downloads RENAME COLUMN url TO normalized_url");
+			
 			perf.Step("Upgrade to version 6");
 			await reporter.NextVersion();
 		}

app/Server/Database/Sqlite/Utils/SqliteExtensions.cs

@@ -19,6 +19,11 @@ static class SqliteExtensions {
 		return cmd;
 	}
 
+	public static void Execute(this ISqliteConnection conn, string sql) {
+		using var cmd = conn.Command(sql);
+		cmd.ExecuteNonQuery();
+	}
+
 	public static async Task<int> ExecuteAsync(this ISqliteConnection conn, [LanguageInjection("sql")] string sql, CancellationToken cancellationToken = default) {
 		await using var cmd = conn.Command(sql);
 		return await cmd.ExecuteNonQueryAsync(cancellationToken);
@@ -31,6 +36,11 @@ static class SqliteExtensions {
 		return reader.Read() ? readFunction(reader) : readFunction(null);
 	}
 
+	public static object? SelectScalar(this ISqliteConnection conn, string sql) {
+		using var cmd = conn.Command(sql);
+		return cmd.ExecuteScalar();
+	}
+
 	public static SqliteCommand Insert(this ISqliteConnection conn, string tableName, (string Name, SqliteType Type)[] columns) {
 		string columnNames = string.Join(',', columns.Select(static c => c.Name));
 		string columnParams = string.Join(',', columns.Select(static c => ':' + c.Name));