Release v39.1

app/Desktop/Common/DatabaseGui.cs

@@ -1,9 +1,11 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Controls;
 using Avalonia.Platform.Storage;
+using Avalonia.Threading;
 using DHT.Desktop.Dialogs.File;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Server.Database;
@@ -41,11 +43,16 @@ static class DatabaseGui {
 		});
 	}
 
-	public static async Task<IDatabaseFile?> TryOpenOrCreateDatabaseFromPath(string path, Window window, Func<Task<bool>> checkCanUpgradeDatabase) {
+	public static async Task<IDatabaseFile?> TryOpenOrCreateDatabaseFromPath(string path, Window window, ISchemaUpgradeCallbacks schemaUpgradeCallbacks) {
+		var prevSynchronizationContext = SynchronizationContext.Current;
+		SynchronizationContext.SetSynchronizationContext(new AvaloniaSynchronizationContext());
+		var taskScheduler = TaskScheduler.FromCurrentSynchronizationContext();
+		SynchronizationContext.SetSynchronizationContext(prevSynchronizationContext);
+		
 		IDatabaseFile? file = null;
 
 		try {
-			file = await SqliteDatabaseFile.OpenOrCreate(path, checkCanUpgradeDatabase);
+			file = await SqliteDatabaseFile.OpenOrCreate(path, schemaUpgradeCallbacks, taskScheduler);
 		} catch (InvalidDatabaseVersionException ex) {
 			await Dialog.ShowOk(window, "Database Error", "Database '" + Path.GetFileName(path) + "' appears to be corrupted (invalid version: " + ex.Version + ").");
 		} catch (DatabaseTooNewException ex) {

app/Desktop/Dialogs/Progress/IProgressCallback.cs

@@ -4,4 +4,5 @@ namespace DHT.Desktop.Dialogs.Progress;
 
 interface IProgressCallback {
 	Task Update(string message, int finishedItems, int totalItems);
+	Task Hide();
 }

app/Desktop/Dialogs/Progress/ProgressDialog.axaml

@@ -32,12 +32,18 @@
         </Style>
     </Window.Styles>
 
-    <StackPanel Margin="20">
+    <ItemsRepeater ItemsSource="{Binding Items}" Margin="0 10">
+        <ItemsRepeater.ItemTemplate>
+            <DataTemplate>
+                <StackPanel Margin="20 10" IsHitTestVisible="{Binding IsVisible}" Opacity="{Binding Opacity}">
                     <DockPanel>
                         <TextBlock DockPanel.Dock="Right" Text="{Binding Items}" Classes="items" />
                         <TextBlock DockPanel.Dock="Left" Text="{Binding Message}" />
                     </DockPanel>
                     <ProgressBar Value="{Binding Progress}" />
                 </StackPanel>
+            </DataTemplate>
+        </ItemsRepeater.ItemTemplate>
+    </ItemsRepeater>
 
 </Window>

app/Desktop/Dialogs/Progress/ProgressDialogModel.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 using Avalonia.Threading;
 using DHT.Desktop.Common;
@@ -9,57 +11,43 @@ namespace DHT.Desktop.Dialogs.Progress;
 sealed class ProgressDialogModel : BaseModel {
 	public string Title { get; init; } = "";
 
-	private string message = "";
-
-	public string Message {
-		get => message;
-		private set => Change(ref message, value);
-	}
-
-	private string items = "";
-
-	public string Items {
-		get => items;
-		private set => Change(ref items, value);
-	}
-
-	private int progress = 0;
-
-	public int Progress {
-		get => progress;
-		private set => Change(ref progress, value);
-	}
+	public IReadOnlyList<ProgressItem> Items { get; } = Array.Empty<ProgressItem>();
 
 	private readonly TaskRunner? task;
 
 	[Obsolete("Designer")]
 	public ProgressDialogModel() {}
 
-	public ProgressDialogModel(TaskRunner task) {
+	public ProgressDialogModel(TaskRunner task, int progressItems = 1) {
+		this.Items = Enumerable.Range(0, progressItems).Select(static _ => new ProgressItem()).ToArray();
 		this.task = task;
 	}
 
 	internal async Task StartTask() {
 		if (task != null) {
-			await task(new Callback(this));
+			await task(Items.Select(static item => new Callback(item)).ToArray());
 		}
 	}
 
-	public delegate Task TaskRunner(IProgressCallback callback);
+	public delegate Task TaskRunner(IReadOnlyList<IProgressCallback> callbacks);
 
 	private sealed class Callback : IProgressCallback {
-		private readonly ProgressDialogModel model;
+		private readonly ProgressItem item;
 
-		public Callback(ProgressDialogModel model) {
-			this.model = model;
+		public Callback(ProgressItem item) {
+			this.item = item;
 		}
 
-		async Task IProgressCallback.Update(string message, int finishedItems, int totalItems) {
+		public async Task Update(string message, int finishedItems, int totalItems) {
 			await Dispatcher.UIThread.InvokeAsync(() => {
-				model.Message = message;
-				model.Items = finishedItems.Format() + " / " + totalItems.Format();
-				model.Progress = 100 * finishedItems / totalItems;
+				item.Message = message;
+				item.Items = totalItems == 0 ? string.Empty : finishedItems.Format() + " / " + totalItems.Format();
+				item.Progress = totalItems == 0 ? 0 : 100 * finishedItems / totalItems;
 			});
 		}
+
+		public Task Hide() {
+			return Update(string.Empty, 0, 0);
+		}
 	}
 }

app/Desktop/Dialogs/Progress/ProgressItem.cs

@@ -0,0 +1,41 @@
+using DHT.Utils.Models;
+
+namespace DHT.Desktop.Dialogs.Progress; 
+
+sealed class ProgressItem : BaseModel {
+	private bool isVisible = false;
+
+	public bool IsVisible {
+		get => isVisible;
+		private set {
+			Change(ref isVisible, value);
+			OnPropertyChanged(nameof(Opacity));
+		}
+	}
+	
+	public double Opacity => IsVisible ? 1.0 : 0.0;
+
+	private string message = "";
+
+	public string Message {
+		get => message;
+		set {
+			Change(ref message, value);
+			IsVisible = !string.IsNullOrEmpty(value);
+		}
+	}
+
+	private string items = "";
+
+	public string Items {
+		get => items;
+		set => Change(ref items, value);
+	}
+
+	private int progress = 0;
+
+	public int Progress {
+		get => progress;
+		set => Change(ref progress, value);
+	}
+}

app/Desktop/Main/Pages/DatabasePageModel.cs

@@ -17,6 +17,7 @@ using DHT.Desktop.Dialogs.TextBox;
 using DHT.Server.Data;
 using DHT.Server.Database;
 using DHT.Server.Database.Import;
+using DHT.Server.Database.Sqlite;
 using DHT.Utils.Logging;
 using DHT.Utils.Models;
 
@@ -77,7 +78,7 @@ sealed class DatabasePageModel : BaseModel {
 		}
 
 		ProgressDialog progressDialog = new ProgressDialog();
-		progressDialog.DataContext = new ProgressDialogModel(async callback => await MergeWithDatabaseFromPaths(Db, paths, progressDialog, callback)) {
+		progressDialog.DataContext = new ProgressDialogModel(async callbacks => await MergeWithDatabaseFromPaths(Db, paths, progressDialog, callbacks[0])) {
 			Title = "Database Merge"
 		};
 
@@ -85,23 +86,10 @@ sealed class DatabasePageModel : BaseModel {
 	}
 
 	private static async Task MergeWithDatabaseFromPaths(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback) {
-		int total = paths.Length;
-
-		DialogResult.YesNo? upgradeResult = null;
-
-		async Task<bool> CheckCanUpgradeDatabase() {
-			upgradeResult ??= total > 1
-				                  ? await DatabaseGui.ShowCanUpgradeMultipleDatabaseDialog(dialog)
-				                  : await DatabaseGui.ShowCanUpgradeDatabaseDialog(dialog);
-
-			return DialogResult.YesNo.Yes == upgradeResult;
-		}
+		var schemaUpgradeCallbacks = new SchemaUpgradeCallbacks(dialog, paths.Length);
 		
 		await PerformImport(target, paths, dialog, callback, "Database Merge", "Database Error", "database file", async path => {
-			SynchronizationContext? prevSyncContext = SynchronizationContext.Current;
-			SynchronizationContext.SetSynchronizationContext(new AvaloniaSynchronizationContext());
-			IDatabaseFile? db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, dialog, CheckCanUpgradeDatabase);
-			SynchronizationContext.SetSynchronizationContext(prevSyncContext);
+			IDatabaseFile? db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, dialog, schemaUpgradeCallbacks);
 
 			if (db == null) {
 				return false;
@@ -116,6 +104,41 @@ sealed class DatabasePageModel : BaseModel {
 		});
 	}
 
+	private sealed class SchemaUpgradeCallbacks : ISchemaUpgradeCallbacks {
+		private readonly ProgressDialog dialog;
+		private readonly int total;
+		private bool? decision;
+		
+		public SchemaUpgradeCallbacks(ProgressDialog dialog, int total) {
+			this.total = total;
+			this.dialog = dialog;
+		}
+
+		public async Task<bool> CanUpgrade() {
+			return decision ??= (total > 1
+				                     ? await DatabaseGui.ShowCanUpgradeMultipleDatabaseDialog(dialog)
+				                     : await DatabaseGui.ShowCanUpgradeDatabaseDialog(dialog)) == DialogResult.YesNo.Yes;
+		}
+
+		public Task Start(int versionSteps, Func<ISchemaUpgradeCallbacks.IProgressReporter, Task> doUpgrade) {
+			return doUpgrade(new NullReporter());
+		}
+
+		private sealed class NullReporter : ISchemaUpgradeCallbacks.IProgressReporter {
+			public Task NextVersion() {
+				return Task.CompletedTask;
+			}
+
+			public Task MainWork(string message, int finishedItems, int totalItems) {
+				return Task.CompletedTask;
+			}
+
+			public Task SubWork(string message, int finishedItems, int totalItems) {
+				return Task.CompletedTask;
+			}
+		}
+	}
+
 	public async void ImportLegacyArchive() {
 		var paths = await window.StorageProvider.OpenFiles(new FilePickerOpenOptions {
 			Title = "Open Legacy DHT Archive",
@@ -128,11 +151,11 @@ sealed class DatabasePageModel : BaseModel {
 		}
 
 		ProgressDialog progressDialog = new ProgressDialog();
-		progressDialog.DataContext = new ProgressDialogModel(async callback => await ImportLegacyArchiveFromPaths(Db, paths, progressDialog, callback)) {
+		progressDialog.DataContext = new ProgressDialogModel(async callbacks => await ImportLegacyArchiveFromPaths(Db, paths, progressDialog, callbacks[0])) {
 			Title = "Legacy Archive Import"
 		};
 
-		await progressDialog.ShowDialog(window);
+		await progressDialog.ShowProgressDialog(window);
 	}
 
 	private static async Task ImportLegacyArchiveFromPaths(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback) {

app/Desktop/Main/Pages/DebugPageModel.cs

@@ -45,7 +45,7 @@ namespace DHT.Desktop.Main.Pages {
 			}
 
 			ProgressDialog progressDialog = new ProgressDialog {
-				DataContext = new ProgressDialogModel(async callback => await GenerateRandomData(channels, users, messages, callback)) {
+				DataContext = new ProgressDialogModel(async callbacks => await GenerateRandomData(channels, users, messages, callbacks[0])) {
 					Title = "Generating Random Data"
 				}
 			};

app/Desktop/Main/Screens/WelcomeScreenModel.cs

@@ -1,10 +1,13 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
 using Avalonia.Controls;
 using DHT.Desktop.Common;
 using DHT.Desktop.Dialogs.Message;
+using DHT.Desktop.Dialogs.Progress;
 using DHT.Server.Database;
+using DHT.Server.Database.Sqlite;
 using DHT.Utils.Models;
 
 namespace DHT.Desktop.Main.Screens;
@@ -39,16 +42,73 @@ sealed class WelcomeScreenModel : BaseModel, IDisposable {
 		}
 
 		dbFilePath = path;
-		Db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, window, CheckCanUpgradeDatabase);
+		Db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, window, new SchemaUpgradeCallbacks(window));
 
 		OnPropertyChanged(nameof(Db));
 		OnPropertyChanged(nameof(HasDatabase));
 	}
 
-	private async Task<bool> CheckCanUpgradeDatabase() {
+	private sealed class SchemaUpgradeCallbacks : ISchemaUpgradeCallbacks {
+		private readonly Window window;
+		
+		public SchemaUpgradeCallbacks(Window window) {
+			this.window = window;
+		}
+
+		public async Task<bool> CanUpgrade() {
 			return DialogResult.YesNo.Yes == await DatabaseGui.ShowCanUpgradeDatabaseDialog(window);
 		}
 
+		public async Task Start(int versionSteps, Func<ISchemaUpgradeCallbacks.IProgressReporter, Task> doUpgrade) {
+			async Task StartUpgrade(IReadOnlyList<IProgressCallback> callbacks) {
+				var reporter = new ProgressReporter(versionSteps, callbacks);
+				await reporter.NextVersion();
+				await Task.Delay(TimeSpan.FromMilliseconds(800));
+				await doUpgrade(reporter);
+				await Task.Delay(TimeSpan.FromMilliseconds(600));
+			}
+
+			await new ProgressDialog {
+				DataContext = new ProgressDialogModel(StartUpgrade, progressItems: 3) {
+					Title = "Upgrading Database"
+				}
+			}.ShowProgressDialog(window);
+		}
+
+		private sealed class ProgressReporter : ISchemaUpgradeCallbacks.IProgressReporter {
+			private readonly IReadOnlyList<IProgressCallback> callbacks;
+			
+			private readonly int versionSteps;
+			private int versionProgress = 0;
+			
+			public ProgressReporter(int versionSteps, IReadOnlyList<IProgressCallback> callbacks) {
+				this.callbacks = callbacks;
+				this.versionSteps = versionSteps;
+			}
+
+			public async Task NextVersion() {
+				await callbacks[0].Update("Upgrading schema version...", versionProgress++, versionSteps);
+				await HideChildren(0);
+			}
+
+			public async Task MainWork(string message, int finishedItems, int totalItems) {
+				await callbacks[1].Update(message, finishedItems, totalItems);
+				await HideChildren(1);
+			}
+
+			public async Task SubWork(string message, int finishedItems, int totalItems) {
+				await callbacks[2].Update(message, finishedItems, totalItems);
+				await HideChildren(2);
+			}
+
+			private async Task HideChildren(int parentIndex) {
+				for (int i = parentIndex + 1; i < callbacks.Count; i++) {
+					await callbacks[i].Hide();
+				}
+			}
+		}
+	}
+
 	public void CloseDatabase() {
 		Dispose();
 		OnPropertyChanged(nameof(Db));

app/Server/Database/Import/LegacyArchiveImport.cs

@@ -21,7 +21,7 @@ public static class LegacyArchiveImport {
 
 	public static async Task<bool> Read(Stream stream, IDatabaseFile db, FakeSnowflake fakeSnowflake, Func<Data.Server[], Task<Dictionary<Data.Server, ulong>?>> askForServerIds) {
 		var perf = Log.Start();
-		var root = await JsonSerializer.DeserializeAsync(stream, LegacyArchiveJsonContext.Default.JsonElement);
+		var root = await JsonSerializer.DeserializeAsync(stream, JsonElementContext.Default.JsonElement);
 
 		try {
 			var meta = root.RequireObject("meta");

app/Server/Database/Sqlite/ISchemaUpgradeCallbacks.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Threading.Tasks;
+
+namespace DHT.Server.Database.Sqlite; 
+
+public interface ISchemaUpgradeCallbacks {
+	Task<bool> CanUpgrade();
+	Task Start(int versionSteps, Func<IProgressReporter, Task> doUpgrade);
+
+	public interface IProgressReporter {
+		Task NextVersion();
+		Task MainWork(string message, int finishedItems, int totalItems);
+		Task SubWork(string message, int finishedItems, int totalItems);
+	}
+}

app/Server/Database/Sqlite/Schema.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using DHT.Server.Database.Exceptions;
@@ -20,12 +19,8 @@ sealed class Schema {
 		this.conn = conn;
 	}
 
-	private void Execute(string sql) {
-		conn.Command(sql).ExecuteNonQuery();
-	}
-
-	public async Task<bool> Setup(Func<Task<bool>> checkCanUpgradeSchemas) {
-		Execute(@"CREATE TABLE IF NOT EXISTS metadata (key TEXT PRIMARY KEY, value TEXT)");
+	public async Task<bool> Setup(ISchemaUpgradeCallbacks callbacks) {
+		conn.Execute(@"CREATE TABLE IF NOT EXISTS metadata (key TEXT PRIMARY KEY, value TEXT)");
 
 		var dbVersionStr = conn.SelectScalar("SELECT value FROM metadata WHERE key = 'version'");
 		if (dbVersionStr == null) {
@@ -38,19 +33,19 @@ sealed class Schema {
 			throw new DatabaseTooNewException(dbVersion);
 		}
 		else if (dbVersion < Version) {
-			var proceed = await checkCanUpgradeSchemas();
+			var proceed = await callbacks.CanUpgrade();
 			if (!proceed) {
 				return false;
 			}
 
-			UpgradeSchemas(dbVersion);
+			await callbacks.Start(Version - dbVersion, async reporter => await UpgradeSchemas(dbVersion, reporter));
 		}
 
 		return true;
 	}
 
 	private void InitializeSchemas() {
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE users (
 		             	id            INTEGER PRIMARY KEY NOT NULL,
 		             	name          TEXT NOT NULL,
@@ -59,7 +54,7 @@ sealed class Schema {
 		             )
 		             """);
 
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE servers (
 		             	id   INTEGER PRIMARY KEY NOT NULL,
 		             	name TEXT NOT NULL,
@@ -67,7 +62,7 @@ sealed class Schema {
 		             )
 		             """);
 
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE channels (
 		             	id        INTEGER PRIMARY KEY NOT NULL,
 		             	server    INTEGER NOT NULL,
@@ -79,7 +74,7 @@ sealed class Schema {
 		             )
 		             """);
 
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE messages (
 		             	message_id INTEGER PRIMARY KEY NOT NULL,
 		             	sender_id  INTEGER NOT NULL,
@@ -89,7 +84,7 @@ sealed class Schema {
 		             )
 		             """);
 
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE attachments (
 		             	message_id     INTEGER NOT NULL,
 		             	attachment_id  INTEGER NOT NULL PRIMARY KEY NOT NULL,
@@ -103,14 +98,14 @@ sealed class Schema {
 		             )
 		             """);
 
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE embeds (
 		             	message_id INTEGER NOT NULL,
 		             	json       TEXT NOT NULL
 		             )
 		             """);
 
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE downloads (
 		             	normalized_url TEXT NOT NULL PRIMARY KEY,
 		             	download_url   TEXT,
@@ -120,7 +115,7 @@ sealed class Schema {
 		             )
 		             """);
 		
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE reactions (
 		             	message_id  INTEGER NOT NULL,
 		             	emoji_id    INTEGER,
@@ -133,15 +128,15 @@ sealed class Schema {
 		CreateMessageEditTimestampTable();
 		CreateMessageRepliedToTable();
 
-		Execute("CREATE INDEX attachments_message_ix ON attachments(message_id)");
-		Execute("CREATE INDEX embeds_message_ix ON embeds(message_id)");
-		Execute("CREATE INDEX reactions_message_ix ON reactions(message_id)");
+		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)");
 
-		Execute("INSERT INTO metadata (key, value) VALUES ('version', " + Version + ")");
+		conn.Execute("INSERT INTO metadata (key, value) VALUES ('version', " + Version + ")");
 	}
 
 	private void CreateMessageEditTimestampTable() {
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE edit_timestamps (
 		             	message_id     INTEGER PRIMARY KEY NOT NULL,
 		             	edit_timestamp INTEGER NOT NULL
@@ -150,7 +145,7 @@ sealed class Schema {
 	}
 
 	private void CreateMessageRepliedToTable() {
-		Execute("""
+		conn.Execute("""
 		             CREATE TABLE replied_to (
 		             	message_id    INTEGER PRIMARY KEY NOT NULL,
 		             	replied_to_id INTEGER NOT NULL
@@ -158,11 +153,13 @@ sealed class Schema {
 		             """);
 	}
 
-	private void NormalizeAttachmentUrls() {
+	private async Task NormalizeAttachmentUrls(ISchemaUpgradeCallbacks.IProgressReporter reporter) {
+		await reporter.SubWork("Preparing attachments...", 0, 0);
+		
 		var normalizedUrls = new Dictionary<long, string>();
 
-		using (var selectCmd = conn.Command("SELECT attachment_id, url FROM attachments")) {
-			using var reader = selectCmd.ExecuteReader();
+		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);
@@ -171,28 +168,39 @@ sealed class Schema {
 			}
 		}
 
-		using var tx = conn.BeginTransaction();
+		await using var tx = conn.BeginTransaction();
 
-		using (var updateCmd = conn.Command("UPDATE attachments SET download_url = url, url = :normalized_url WHERE attachment_id = :attachment_id")) {
+		int totalUrls = normalizedUrls.Count;
+		int processedUrls = -1;
+
+		await using (var updateCmd = conn.Command("UPDATE attachments SET download_url = url, url = :normalized_url WHERE attachment_id = :attachment_id")) {
 			updateCmd.Parameters.Add(":attachment_id", SqliteType.Integer);
 			updateCmd.Parameters.Add(":normalized_url", SqliteType.Text);
 				
 			foreach (var (attachmentId, normalizedUrl) in normalizedUrls) {
+				if (++processedUrls % 1000 == 0) {
+					await reporter.SubWork("Updating URLs...", processedUrls, totalUrls);
+				}
+
 				updateCmd.Set(":attachment_id", attachmentId);
 				updateCmd.Set(":normalized_url", normalizedUrl);
 				updateCmd.ExecuteNonQuery();
 			}
 		}
 		
-		tx.Commit();
+		await reporter.SubWork("Updating URLs...", totalUrls, totalUrls);
+		
+		await tx.CommitAsync();
 	}
 
-	private void NormalizeDownloadUrls() {
+	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>();
 
-		using (var selectCmd = conn.Command("SELECT url FROM downloads ORDER BY CASE WHEN status = 200 THEN 0 ELSE 1 END")) {
-			using var reader = selectCmd.ExecuteReader();
+		await using (var selectCmd = conn.Command("SELECT url FROM downloads ORDER BY CASE WHEN status = 200 THEN 0 ELSE 1 END")) {
+			await using var reader = await selectCmd.ExecuteReaderAsync();
 
 			while (reader.Read()) {
 				var originalUrl = reader.GetString(0);
@@ -204,68 +212,106 @@ sealed class Schema {
 			}
 		}
 
-		using var tx = conn.BeginTransaction();
+		conn.Execute("PRAGMA cache_size = -20000");
 
-		using (var deleteCmd = conn.Delete("downloads", ("url", SqliteType.Text))) {
+		SqliteTransaction tx;
+		
+		await using (tx = conn.BeginTransaction()) {
+			await reporter.SubWork("Deleting duplicates...", 0, 0);
+
+			await using (var deleteCmd = conn.Delete("downloads", ("url", SqliteType.Text))) {
 				foreach (var duplicateUrl in duplicateUrlsToDelete) {
 					deleteCmd.Set(":url", duplicateUrl);
 					deleteCmd.ExecuteNonQuery();
 				}
 			}
 			
-		using (var updateCmd = conn.Command("UPDATE downloads SET download_url = :download_url, url = :normalized_url WHERE url = :download_url")) {
+			await tx.CommitAsync();
+		}
+
+		int totalUrls = normalizedUrlsToOriginalUrls.Count;
+		int processedUrls = -1;
+
+		tx = conn.BeginTransaction();
+		
+		await using (var updateCmd = conn.Command("UPDATE downloads SET download_url = :download_url, url = :normalized_url WHERE url = :download_url")) {
 			updateCmd.Parameters.Add(":normalized_url", SqliteType.Text);
 			updateCmd.Parameters.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 = conn.BeginTransaction();
+					updateCmd.Transaction = tx;
+				}
+
 				updateCmd.Set(":normalized_url", normalizedUrl);
 				updateCmd.Set(":download_url", downloadUrl);
 				updateCmd.ExecuteNonQuery();
 			}
 		}
 		
-		tx.Commit();
+		await reporter.SubWork("Updating URLs...", totalUrls, totalUrls);
+		
+		await tx.CommitAsync();
+		await tx.DisposeAsync();
+		
+		conn.Execute("PRAGMA cache_size = -2000");
 	}
 
-	private void UpgradeSchemas(int dbVersion) {
+	private async Task UpgradeSchemas(int dbVersion, ISchemaUpgradeCallbacks.IProgressReporter reporter) {
 		var perf = Log.Start("from version " + dbVersion);
 
-		Execute("UPDATE metadata SET value = " + Version + " WHERE key = 'version'");
+		conn.Execute("UPDATE metadata SET value = " + Version + " WHERE key = 'version'");
 
 		if (dbVersion <= 1) {
-			Execute("ALTER TABLE channels ADD parent_id INTEGER");
+			await reporter.MainWork("Applying schema changes...", 0, 1);
+			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();
 
-			Execute("""
+			conn.Execute("""
 			             INSERT INTO edit_timestamps (message_id, edit_timestamp)
 			             SELECT message_id, edit_timestamp
 			             FROM messages
 			             WHERE edit_timestamp IS NOT NULL
 			             """);
 
-			Execute("""
+			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
 			             """);
 
-			Execute("ALTER TABLE messages DROP COLUMN replied_to_id");
-			Execute("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");
 			
-			Execute("VACUUM");
+			await reporter.MainWork("Vacuuming the database...", 1, 1);
+			conn.Execute("VACUUM");
 			perf.Step("Vacuum");
+			
+			await reporter.NextVersion();
 		}
 
 		if (dbVersion <= 3) {
-			Execute("""
+			conn.Execute("""
 			             CREATE TABLE downloads (
 			             	url    TEXT NOT NULL PRIMARY KEY,
 			             	status INTEGER NOT NULL,
@@ -275,25 +321,35 @@ sealed class Schema {
 			             """);
 			
 			perf.Step("Upgrade to version 4");
+			await reporter.NextVersion();
 		}
 
 		if (dbVersion <= 4) {
-			Execute("ALTER TABLE attachments ADD width INTEGER");
-			Execute("ALTER TABLE attachments ADD height INTEGER");
+			await reporter.MainWork("Applying schema changes...", 0, 1);
+			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) {
-			Execute("ALTER TABLE attachments ADD download_url TEXT");
-			Execute("ALTER TABLE downloads ADD download_url TEXT");
+			await reporter.MainWork("Applying schema changes...", 0, 3);
+			conn.Execute("ALTER TABLE attachments ADD download_url TEXT");
+			conn.Execute("ALTER TABLE downloads ADD download_url TEXT");
 			
-			NormalizeAttachmentUrls();
-			NormalizeDownloadUrls();
+			await reporter.MainWork("Updating attachments...", 1, 3);
+			await NormalizeAttachmentUrls(reporter);
 			
-			Execute("ALTER TABLE attachments RENAME COLUMN url TO normalized_url");
-			Execute("ALTER TABLE downloads RENAME COLUMN url TO normalized_url");
+			await reporter.MainWork("Updating downloads...", 2, 3);
+			await NormalizeDownloadUrls(reporter);
+			
+			await reporter.MainWork("Applying schema changes...", 3, 3);
+			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();
 		}
 
 		perf.End();

app/Server/Database/Sqlite/SqliteDatabaseFile.cs

@@ -18,7 +18,7 @@ namespace DHT.Server.Database.Sqlite;
 public sealed class SqliteDatabaseFile : IDatabaseFile {
 	private const int DefaultPoolSize = 5;
 
-	public static async Task<SqliteDatabaseFile?> OpenOrCreate(string path, Func<Task<bool>> checkCanUpgradeSchemas) {
+	public static async Task<SqliteDatabaseFile?> OpenOrCreate(string path, ISchemaUpgradeCallbacks schemaUpgradeCallbacks, TaskScheduler computeTaskResultScheduler) {
 		var connectionString = new SqliteConnectionStringBuilder {
 			DataSource = path,
 			Mode = SqliteOpenMode.ReadWriteCreate,
@@ -27,12 +27,16 @@ public sealed class SqliteDatabaseFile : IDatabaseFile {
 		var pool = new SqliteConnectionPool(connectionString, DefaultPoolSize);
 		bool wasOpened;
 
-		using (var conn = pool.Take()) {
-			wasOpened = await new Schema(conn).Setup(checkCanUpgradeSchemas);
+		try {
+			using var conn = pool.Take();
+			wasOpened = await new Schema(conn).Setup(schemaUpgradeCallbacks);
+		} catch (Exception) {
+			pool.Dispose();
+			throw;
 		}
 
 		if (wasOpened) {
-			return new SqliteDatabaseFile(path, pool);
+			return new SqliteDatabaseFile(path, pool, computeTaskResultScheduler);
 		}
 		else {
 			pool.Dispose();
@@ -49,13 +53,13 @@ public sealed class SqliteDatabaseFile : IDatabaseFile {
 	private readonly AsyncValueComputer<long>.Single totalAttachmentsComputer;
 	private readonly AsyncValueComputer<long>.Single totalDownloadsComputer;
 
-	private SqliteDatabaseFile(string path, SqliteConnectionPool pool) {
+	private SqliteDatabaseFile(string path, SqliteConnectionPool pool, TaskScheduler computeTaskResultScheduler) {
 		this.log = Log.ForType(typeof(SqliteDatabaseFile), System.IO.Path.GetFileName(path));
 		this.pool = pool;
 
-		this.totalMessagesComputer = AsyncValueComputer<long>.WithResultProcessor(UpdateMessageStatistics).WithOutdatedResults().BuildWithComputer(ComputeMessageStatistics);
-		this.totalAttachmentsComputer = AsyncValueComputer<long>.WithResultProcessor(UpdateAttachmentStatistics).WithOutdatedResults().BuildWithComputer(ComputeAttachmentStatistics);
-		this.totalDownloadsComputer = AsyncValueComputer<long>.WithResultProcessor(UpdateDownloadStatistics).WithOutdatedResults().BuildWithComputer(ComputeDownloadStatistics);
+		this.totalMessagesComputer = AsyncValueComputer<long>.WithResultProcessor(UpdateMessageStatistics, computeTaskResultScheduler).WithOutdatedResults().BuildWithComputer(ComputeMessageStatistics);
+		this.totalAttachmentsComputer = AsyncValueComputer<long>.WithResultProcessor(UpdateAttachmentStatistics, computeTaskResultScheduler).WithOutdatedResults().BuildWithComputer(ComputeAttachmentStatistics);
+		this.totalDownloadsComputer = AsyncValueComputer<long>.WithResultProcessor(UpdateDownloadStatistics, computeTaskResultScheduler).WithOutdatedResults().BuildWithComputer(ComputeDownloadStatistics);
 
 		this.Path = path;
 		this.Statistics = new DatabaseStatistics();

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

@@ -5,14 +5,19 @@ using Microsoft.Data.Sqlite;
 namespace DHT.Server.Database.Sqlite.Utils;
 
 static class SqliteExtensions {
+	public static SqliteTransaction BeginTransaction(this ISqliteConnection conn) {
+		return conn.InnerConnection.BeginTransaction();
+	}
+
 	public static SqliteCommand Command(this ISqliteConnection conn, string sql) {
 		var cmd = conn.InnerConnection.CreateCommand();
 		cmd.CommandText = sql;
 		return cmd;
 	}
 
-	public static SqliteTransaction BeginTransaction(this ISqliteConnection conn) {
-		return conn.InnerConnection.BeginTransaction();
+	public static void Execute(this ISqliteConnection conn, string sql) {
+		using var cmd = conn.Command(sql);
+		cmd.ExecuteNonQuery();
 	}
 
 	public static object? SelectScalar(this ISqliteConnection conn, string sql) {

app/Server/Endpoints/BaseEndpoint.cs

@@ -60,6 +60,10 @@ abstract class BaseEndpoint {
 	protected abstract Task<IHttpOutput> Respond(HttpContext ctx);
 
 	protected static async Task<JsonElement> ReadJson(HttpContext ctx) {
-		return await ctx.Request.ReadFromJsonAsync<JsonElement?>() ?? throw new HttpException(HttpStatusCode.UnsupportedMediaType, "This endpoint only accepts JSON.");
+		try {
+			return await ctx.Request.ReadFromJsonAsync(JsonElementContext.Default.JsonElement);
+		} catch (JsonException) {
+			throw new HttpException(HttpStatusCode.UnsupportedMediaType, "This endpoint only accepts JSON.");
+		}
 	}
 }

app/Utils/Http/JsonElementContext.cs

@@ -1,8 +1,8 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
 
-namespace DHT.Server.Database.Import;
+namespace DHT.Utils.Http;
 
 [JsonSourceGenerationOptions(PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase, GenerationMode = JsonSourceGenerationMode.Default)]
 [JsonSerializable(typeof(JsonElement))]
-sealed partial class LegacyArchiveJsonContext : JsonSerializerContext {}
+public sealed partial class JsonElementContext : JsonSerializerContext {}

app/Version.cs

@@ -8,5 +8,5 @@ using DHT.Utils;
 namespace DHT.Utils; 
 
 static class Version {
-	public const string Tag = "39.0.0.0";
+	public const string Tag = "39.1.0.0";
 }